bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular interactions arising in polyethylene‐bentonite nanocomposites
Authors: Bonilla‐Blancas A. E. , Romero‐Ibarra I. C. , Vazquez‐Arenas J. , Sanchez‐Solis A. , Manero O. , Alvarez‐Ramirez J. 
Published: September 2018

ABSTRACTHigh density polyethylene (HDPE), linear low density polyethylene (LLDPE) and low density polyethylene (LDPE) are blended, and compared against a similar mixture but functionalized LDPE with maleic anhydride (MAh), HDPE‐LLDPE‐LDPE‐g‐MAh. In order to obtain nanocomposites from these polymer blends, a modified bentonite was added by incorporating l‐lysine into the bentonite galleries by melt extrusion. The resulting nanocomposites presented improved mechanical properties linked to strong polymer‐bentonite interactions and exfoliated structures as verified by transmission electron microscopy and rheometry. A detailed analysis of the feasible polymer‐bentonite interactions was conducted, of particular concern between the polar MAh groups and the intercalated l‐lysine. To gain further insights into the type of molecular interactions (i.e. polymer‐bentonite), a model nanocomposite was synthesized in solution to carry out further assessments through NMR, infrared spectroscopy and rheology analysis. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 46920.
Clinical epidemiology of congenital heart disease in Nigerian children, 2012–2017
Authors: Ekure Ekanem N. , Kalu Nnenna , Sokunbi Ogochukwu J. , Kruszka Paul , Olusegun‐Joseph Akinsanya D. , Ikebudu Desmond , Bala David , Muenke Maximilian , Adeyemo Adebowale 
Published: September 2018

BackgroundCongenital heart diseases (CHDs) affect ~1% of newborns and are a significant cause of morbidity and mortality in children. We present the clinical epidemiology of CHD as seen in a large university medical center in Nigeria.MethodsParticipants were 767 children with echocardiographically confirmed CHD seen over a 5‐year period at the Lagos University Teaching Hospital, Nigeria.ResultsClinical presentation was often late with just over half (58.1%) presenting in infancy. The male:female distribution was 1:1. The predominant types of cardiac lesion seen were septal defects (43%), conotruncal defects (23.7%), atrioventricular septal defects (9.8%), and right ventricular outflow tract obstruction (7.3%). Cyanotic CHD was seen in 28.4% of cases and the single most common cyanotic CHD was Tetralogy of Fallot (13.4%). Children with cyanotic CHD were older (p = .002), had more severe lesions (p < .0001) and were more likely to have cardiac intervention (p < .0001). Extracardiac malformations were present in nearly one‐third of the children. Syndromes associated with CHD were identified in 15.5% of the children and included Down syndrome (11.9%), congenital rubella syndrome (1.0%), and Marfan syndrome (0.7%).ConclusionsThis study is a large case series of CHD from a single site in sub‐Saharan Africa utilizing clinical, epidemiological, and developmental considerations. It provides a rich and up‐to‐date description of the clinical epidemiology of CHD in Nigerian children while yielding data that could be useful for designing genetic, molecular, and biomarker studies.
Emotional intelligence (EI) and self‐directed learning: Examining their relation and contribution to better student learning outcomes in higher education
Authors: Zhoc Karen C. H. , Chung Tony S. H. , King Ronnel B. 
Published: September 2018

Self‐directed learning is recognised as a key goal of higher education. To facilitate self‐directed learning, emotional intelligence (EI), which encompasses the ability to regulate one's own emotions and to generate positive emotions, is important. The present study aimed to examine the effects ofEIon self‐directed learning and howEIand self‐directed learning contribute to key learning outcomes in higher education, including grade point average (GPA), generic learning outcomes (including social, cognitive and self‐growth outcomes) and students’ satisfaction with their university experience. The study adopted a prospective longitudinal design with 560 first‐year undergraduate students completing different measures at the beginning and end of the academic year. Results of the structural equation modelling showed thatEIhad a strong effect on self‐directed learning, which in turn was positively associated withGPAand various generic learning outcomes that are related to students’ satisfaction with the university experience. To better delineate the relationship betweenEIand self‐directed learning, multiple regression was performed. Results indicated that three key emotional abilities—emotional regulation of the self (ERS), appraisal of emotions in the self (AES) and emotional regulation of others (ERO)—were positively associated with self‐directed learning. This study provided empirical evidence that students who are more emotionally intelligent are more self‐directed, leading to higher achievement in both academic and generic development, which in turn results in higher university satisfaction. Implications of the findings are discussed.
Power of the Wilcoxon–Mann–Whitney test for non‐inferiority in the presence of death‐censored observations
Authors: Schmidtmann Irene , Konstantinides Stavros , Binder Harald 
Published: September 2018

AbstractIn clinical trials with patients in a critical state, death may preclude measurement of a quantitative endpoint of interest, and even early measurements, for example for intention‐to‐treat analysis, may not be available. For example, a non‐negligible proportion of patients with acute pulmonary embolism will die before 30 day measurements on the efficacy of thrombolysis can be obtained. As excluding such patients may introduce bias, alternative analyses, and corresponding means for sample size calculation are needed. We specifically consider power analysis in a randomized clinical trial setting in which the goal is to demonstrate noninferiority of a new treatment as compared to a reference treatment. Also, a nonparametric approach may be needed due to the distribution of the quantitative endpoint of interest. While some approaches have been developed in a composite endpoint setting, our focus is on the continuous endpoint affected by death‐related censoring, for which no approach for noninferiority is available. We propose a solution based on ranking the quantitative outcome and assigning worst rank scores to the patients without quantitative outcome because of death. Based on this, we derive power formulae for a noninferiority test in the presence of death‐censored observations, considering settings with and without ties. The approach is illustrated for an exemplary clinical trial in pulmonary embolism. The results there show a substantial effect of death on power, also depending on differential effects in the two trial arms. Therefore, use of the proposed formulae is advisable whenever there is death to be expected before measurement of a quantitative primary outcome of interest.
Synthetic repetitive extragenic palindromic (REP) sequence as an efficient mRNA stabilizer for protein production and metabolic engineering in prokaryotic cells
Authors: Deng Chen , Lv Xueqin , Li Jianghua , Liu Yanfeng , Du Guocheng , Amaro Rodrigo Ledesma , Liu Long 
Published: September 2018

AbstractIn prokaryotic cells, 3′–5′ exonucleases can attenuate messenger RNA (mRNA) directionally from the direction of the 3′–5′ untranslated region (UTR), and thus improving the stability of mRNAs without influencing normal cell growth and metabolism is a key challenge for protein production and metabolic engineering. Herein, we significantly improved mRNA stability by using synthetic repetitive extragenic palindromic (REP) sequences as an effective mRNA stabilizer in two typical prokaryotic microbes, namely, Escherichia coli for the production of cyclodextrin glucosyltransferase (CGTase) and
Corynebacterium glutamicum for the production of
N‐acetylglucosamine (GlcNAc). First, we performed a high‐throughput screen to select 4 out of 380 REP sequences generated by randomizing 6 nonconservative bases in the REP sequence designed as the degenerate base “N.” Secondly, the REP sequence was inserted at several different positions after the stop codon of the CGTase‐encoding gene. We found that mRNA stability was improved only when the space between the REP sequence and stop codon was longer than 12 base pairs (bp). Then, by reconstructing the spacer sequence and secondary structure of the REP sequence, a REP sequence with 8 bp in a stem‐loop was obtained, and the CGTase activity increased from 210.6 to 291.5 U/ml. Furthermore, when this REP sequence was added to the 3′‐UTR of glucosamine‐6‐phosphate
N‐acetyltransferase 1 (
GNA1), which is a gene encoding a key enzyme GNA1 in the GlcNAc synthesis pathway, the GNA1 activity was increased from 524.8 to 890.7 U/mg, and the GlcNAc titer was increased from 4.1 to 6.0 g/L in
C.
glutamicum. These findings suggest that the REP sequence plays an important function as an mRNA stabilizer in prokaryotic cells to stabilize its 3′‐terminus of the mRNA by blocking the processing action of the 3′–5′ exonuclease. Overall, this study provides new insight for the high‐efficiency overexpression of target genes and pathway fine‐tuning in bacteria.
Chemical Composition, Security and Bioactivity of the Red Pigment from Penicillium purpurogenum Li‐3
Authors: Jin Hong‐Jie , Zhang Xin , Cao Hong , Niu Yu‐Jing , Li Chun , Liu Hong 
Published: September 2018

AbstractThe chemical composition, security and bioactivity of pigments from Penicillium purpurogenum Li‐3 strain screened by our group were firstly studied in this work. DPPH and the filter disc diffusion method were used to determine the biological activities of the red pigments. The pigment was characterized by UV/VIS, FT‐IR, NMR and UPLC‐Q‐TOF‐MS. HPLC/MS was used to detect mycotoxins (citrinin) in fermentation broth. An acute toxicity was detected in the embryos of zebrafish. As a consequence, the crude red pigment from the AcOEt fraction showed better DPPH scavenge capacity and antibacterial activity. Spectroscopic (UV, FT‐IR, 13C‐NMR) and UPLC‐Q‐TOF‐MS analysis revealed that the Penicillium purpurogenum Li‐3 red pigment (RPs) was monascus‐like pigment and its molecular weight was 439.1997. Moreover, the red pigment was shown to be weak cytotoxic against the zebrafish embryos. The yield of the red pigment increased 69 % under optimized culture conditions. These outstanding properties will enlarge the application of RPs for natural food additives, new antioxidant and antibacterial drug development.
Onyx is the new black
Authors: Belardi Jorge A. , Albertal Mariano 
Published: September 2018

Key Points

Ultrathin drug‐eluting stent (DES) constitute the workhorse stent for routine percutaneous coronary interventions.
The Resolute Onyx is a novel radiopaque, ultrathin DES with very low crossing profile.
In the present prospective, single arm study, Resolute (R) Onyx was non‐inferior and superior to a prior R iteration, in terms of late loss at 8 months follow‐up.
Data are only preliminary due to sample size and length of follow‐up.
Radial hemostasis: Harder, better, faster, stronger?
Authors: Seto Arnold H. , Kern Morton J. 
Published: September 2018

Key Points

Hemostasis protocols after transradial catheterization are highly variable.
Hemostatic patches potentially speed hemostasis at the arteriotomy site, improving efficiency and throughput.
Larger trials of hemostatic patches are needed to demonstrate their superiority to conventional approaches.
Construction of NiCo2S4@NiMoO4 Core‐Shell Nanosheet Arrays with Superior Electrochemical Performance for Asymmetric Supercapacitors
Authors: Chen Sanming , Zhang Zhipeng , Zeng Weijia , Chen Jiaxiang , Deng Libo 
Published: September 2018

AbstractIn this work, we develop hierarchical NiCo2S4@NiMoO4 nanosheet arrays directly anchored on nickel foam by a hydrothermal method. The self‐supported core‐shell architecture take advantage of high electroactive surface area, rapid channels for ion diffusion and electron transport, and the synergistic contributions from both the NiCo2S4 core and NiMoO4 shell. Remarkably, the NiCo2S4@NiMoO4 electrode showed high specific capacitance of 1487.6 F g−1 at a current density of 1 A g−1 and superior cycling stability (89.7 % capacitance retention after 8000 charge‐discharge cycles). An asymmetric supercapacitor (ASC) with an optimized cell voltage of 1.6 V was assembled by using activated carbon (AC) as the negative electrode and NiCo2S4@NiMoO4 electrode as the positive electrode, achieving an extraordinary energy density of 53.2 Wh kg−1 at a power density of 560 W kg−1, and remained 34.8 Wh kg−1 at a maximum power density of 11.2 kW kg−1. The outstanding electrochemical behavior indicate that the NiCo2S4@NiMoO4 nanosheet arrays hold great promise for high‐performance energy storage devices.
Flexible and Tailorable Na−CO2 Batteries Based on an All‐Solid‐State Polymer Electrolyte
Authors: Wang Xingchao , Zhang Xuejing , Lu Yong , Yan Zhenhua , Tao Zhanliang , Jia Dianzeng , Chen Jun 
Published: September 2018

AbstractRechargeable Na< C‐>CO2 batteries coupling Na anodes with the greenhouse gas CO2 cathode are promising energy‐storage devices due to the high energy density, environmental friendliness and cost‐effectiveness. However, major challenges impeding the application of Na−CO2 batteries are safety concern regarding the leakage of flammable liquid electrolytes and the instability of the Na anodes. Herein, we construct all‐solid‐state flexible Na−CO2 batteries by designing an integrated structure built of a Na anode, poly(ethylene oxide)/NaClO4/SiO2 electrolyte and multiwall carbon nanotubes cathode. The batteries exhibit much improved safety and good cyclability (240 cycles with an overpotential increase of ∼0.4 V). Remarkably, we fabricated lab scale‐up integrated batteries (8×16 cm2), which display large capacity (450 mAh) and high energy density (173 Wh kg−1). Moreover, the integrated batteries show excellent bendability (≥1,000 times), foldability in individual shapes, as well as stable operation time (80 h) at bending states of 0° to 360°. Our work demonstrates a way to exploit flexible and safe solid‐state Na−CO2 batteries.
Designing Eco‐Sustainable Dye‐Sensitized Solar Cells by the Use of a Menthol‐Based Hydrophobic Eutectic Solvent as an Effective Electrolyte Medium
Authors: Boldrini Chiara Liliana , Manfredi Norberto , Perna Filippo Maria , Capriati Vito , Abbotto Alessandro 
Published: September 2018

AbstractThe use of a hydrophobic eutectic solvent based on dl‐menthol and a naturally occurring acid such as acetic acid has been tested as an eco‐friendly electrolyte medium in dye‐sensitized solar cells. In the presence of a de‐aggregating agent and a representative hydrophobic organic photosensitizer, the corresponding devices displayed relatively good power conversion efficiencies in very thin active layers. In particular, the higher cell photovoltage detected in comparison to devices based on toxic and volatile organic compounds may stem from a more efficient interface interaction, as suggested by electrochemical impedance spectroscopy studies showing greater charge recombination resistance and electron lifetime.
A Universal Geochemical Scenario for Formamide Condensation and Prebiotic Chemistry
Authors: Saladino Raffaele , Di Mauro Ernesto , García‐Ruiz Juan Manuel 
Published: September 2018

AbstractThe condensation of formamide has been shown to be a robust chemical pathway affording molecules necessary for the origin of life. It has been experimentally demonstrated that condensation reactions of formamide are catalyzed by a number of minerals, including silicates, phosphates, sulfides, zirconia, and borates, and by cosmic dusts and meteorites. However, a critical discussion of the catalytic power of the tested minerals, and the geochemical conditions under which the condensation would occur, is still missing. We show here that mineral self‐assembled structures forming under alkaline silica‐rich solutions are excellent catalysts for the condensation of formamide with respect to other minerals. We also propose that these structures were likely forming as early as 4.4 billion years ago when the whole earth surface was a reactor, a global scale factory, releasing large amounts of organic compounds. Our experimental results suggest that the conditions required for the synthesis of the molecular bricks from which life self‐assembles, rather than being local and bizarre, appears to be universal and geologically rather conventional.
Improving the Halogen–Magnesium Exchange by using New Turbo‐Grignard Reagents
Authors: Ziegler Dorothée S. , Wei Baosheng , Knochel Paul 
Published: September 2018

AbstractThis Minireview describes the scope of the halogen–magnesium exchange. It shows that the use of the turbo‐Grignard reagent (iPrMgCl⋅LiCl) greatly enhances the rate of the Br– and I–Mg exchange. Furthermore, this magnesium reagent allows the performance of a fast sulfoxide–magnesium exchange. Also, the use of sBuMgOR⋅LiOR (R=2‐ethylhexyl) enables a Br–Mg exchange in toluene leading to various Grignard reagents in toluene. Additionally, the new exchange reagent sBu2Mg⋅2 LiOR (R=2‐ethylhexyl) further increases the rate of the halogen–magnesium exchange allowing one to perform a chlorine–magnesium exchange for aromatic chlorides bearing an ortho‐methoxy substituent in toluene.
Biofunctionalization of Nano Channels by Direct In‐Pore Solid‐Phase Peptide Synthesis
Authors: Brodrecht Martin , Breitzke Hergen , Gutmann Torsten , Buntkowsky Gerd 
Published: September 2018

AbstractDiatom biosilica are highly complex inorganic/organic hybrid materials. To get deeper insights on their structure at a molecular level, model systems that mimic the complex natural compounds were synthesized and characterized. A simple and efficient peptide immobilization strategy was developed, which uses a well‐ordered porous silica material as a support and commercially available Fmoc‐amino acids, similar to the known solid‐phase peptide synthesis. As an example, Fmoc‐glycine and Fmoc‐phenylalanine are immobilized on the silica support. The success of functionalization was investigated by 13C CP MAS and 29Si CP MAS solid‐state NMR. Thermogravimetric analysis (TGA) and elemental analysis (EA) were performed to quantify the functionalization. Changes of the specific surface area, pore volume, and pore diameters in all modification steps were studied by Brunauer–Emmett–Teller based nitrogen adsorption–desorption measurements (BET). The combination of the analytical methods provided high grafting densities of 2.1±0.2 molecules/nm2 on the surface. Furthermore, they allowed for monitoring chemical changes on the pore surface and changes of the pore properties of the material during the different functionalization steps. This universal approach is suitable for the selective synthesis of pores with tunable surface‐peptide functionalization, with applications to the synthesis of a big variety of silica–peptide model systems, which in the future may lead to a deeper understanding of complex biological systems.
Li2BaSc(BO3)2F and LiBa2Pb(BO3)2F with Layered Structures featuring Special Li−O/F Configurations
Authors: Chen Yanna , Zhang Min , Hu Cong , Wu Hongping , Yang Zhihua , Pan Shilie 
Published: September 2018

AbstractTwo new borate fluorides, Li2BaSc(BO3)2F and LiBa2Pb(BO3)2F, with layered structures featuring special Li−O/F configurations have been successfully prepared by the high‐temperature solution method. Li2BaSc(BO3)2F contains the first reported 2∞[Li2(BO3)2F] double layers that are evolved from 2∞[Be2BO3F2] single layers in KBe2BO3F2 through substituting BeO4 with the LiO3F tetrahedra. The adjacent double layers are tightly connected by strong Sc−O bonds, generating the strongest interlayer bond and smallest interlayer distance among KBe2BO3F2 derivatives with double‐layered structures. LiBa2Pb(BO3)2F features 2∞[Li(BO3)2F] single layers built up of special LiO4F2 octahedra and the BO3 triangles. To our best knowledge, the LiO4F2 octahedron is observed for the first time in borates. Besides, the LiO4F2 octahedra construct unique 1∞[LiO4F] straight chains through sharing apical F atoms, which is different from the configurations of the similar six‐coordinated LiO6 octahedra in other borates.
Reduced Graphene Oxide Chemically Modified with Aggregation‐Induced Emission Polymer for Solid‐State Optical Limiter
Authors: Liu Zhiwei , Dong Ningning , Jiang Peng , Wang Kexin , Wang Jun , Chen Yu 
Published: September 2018

AbstractAggregation‐induced emission (AIE) materials are usually not suitable for constructing solid nonlinear optical (NLO) devices because strong solid‐state aggregation behavior would shorten the excited‐state lifetime, add relaxation pathways, and thereby reduce effective NLO absorption. To address this problem a newly synthesized AIE material, poly{[9,9‐bis(6‐azidohexyl)‐9H‐fluorene]‐alt‐(1,1,2,2‐tetraphenylethene)} (PAHFTP), was treated with reduced graphene oxide (RGO) to give the soluble derivative of poly[(9,9‐dihexyl‐9H‐fluorene)‐alt‐(1,1,2,2‐tetraphenylethene)] (PFTP) covalently grafted onto RGO (PFTP‐RGO). Upon covalent grafting of PAHFTP onto the RGO surface, about 91.89 % of the fluorescence intensity of the PAHFTP film was quenched due to electron transfer from PFTP to RGO, which yielded PFTP.+–RGO.− radical‐ion pairs. The as‐prepared PFTP‐RGO was embedded into a non‐optically active poly(methyl methacrylate) (PMMA) matrix to produce the PFTP‐RGO/PMMA film with good optical quality. As expected, the PAHFTP/PMMA film did not show any NLO response. In contrast to the PFTP‐RGO/PMMA and RGO/PMMA films, the annealed PFTP‐RGO/PMMA exhibited superior OL performance, with low OL thresholds of 0.24 GW cm−2 (1.44 J cm−2) at 532 nm and 0.18 GW cm−2 (1.08 J cm−2) at 1064 nm. The damage thresholds of the annealed PFTP‐RGO/PMMA film are around 33.88 J cm−2 at 900 μJ at 532 nm and 37.32 J cm−2 at 1000 μJ at 1064 nm, respectively.
How Do Substrates Bind to a Bifunctional Thiourea Catalyst? A Vibrational CD Study on Carboxylic Acid Binding
Authors: Kreienborg Nora M. , Merten Christian 
Published: September 2018

AbstractKnowledge about the active conformation of an asymmetric catalyst is highly valuable in order to understand its stereoinductive power, but spectroscopic access to these structures is often limited. For the example of Takemoto's bifunctional thiourea, we demonstrate the capability of VCD spectroscopy to characterize the conformational preferences of the catalyst with and without having a reactant bound to it. In particular we show that the binding orientation of carboxylic acids can easily be derived from a computationally guided analysis of the spectra. Moreover, we identify characteristic marker bands, which are only visible in the VCD spectra of the catalyst/acid mixtures but not in the corresponding IR spectra. Lastly, we also discuss the problem that the popular DFT functional M06‐2X, which we found to perform exceptionally well in the calculations of vibrational frequencies for fluorinated molecules, predicts incorrect structures of the molecular clusters. We relate this poor performance in predicting the structure of the binding topologies to an overestimation of dispersive CH–π and π–π interactions, which occur due to a neglect of the solvent molecules in the clusters. VCD spectroscopy is thus shown to be a powerful tool to identify and subsequently correct such mispredictions of solution‐phase structures.