bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermally Activated Delayed Fluorescence in a Y3N@C80 Endohedral Fullerene: Time‐Resolved Luminescence and EPR Studies
Authors: Zalibera Michal , Krylov Denis S. , Karagiannis Dimitrios , Will Paul‐Anton , Ziegs Frank , Schiemenz Sandra , Lubitz Wolfgang , Reineke Sebastian , Savitsky Anton , Popov Alexey A. 
Published: November 2017

AbstractThe endohedral fullerene Y3N@C80 exhibits luminescence with reasonable quantum yield and extraordinary long lifetime. By variable‐temperature steady‐state and time‐resolved luminescence spectroscopy, it is demonstrated that above 60 K the Y3N@C80 exhibits thermally activated delayed fluorescence with maximum emission at 120 K and a negligible prompt fluorescence. Below 60 K, a phosphorescence with a lifetime of 192±1 ms is observed. Spin distribution and dynamics in the triplet excited state is investigated with X‐ and W‐band EPR and ENDOR spectroscopies and DFT computations. Finally, electroluminescence of the Y3N@C80/PFO film is demonstrated opening the possibility for red‐emitting fullerene‐based organic light‐emitting diodes (OLEDs).
MoB/g‐C3N4 Interface Materials as a Schottky Catalyst to Boost Hydrogen Evolution
Authors: Zhuang Zechao , Li Yong , Li Zilan , Lv Fan , Lang Zhiquan , Zhao Kangning , Zhou Liang , Moskaleva Lyudmila , Guo Shaojun , Mai Liqiang 
Published: November 2017

AbstractProton adsorption on metallic catalysts is a prerequisite for efficient hydrogen evolution reaction (HER). However, tuning proton adsorption without perturbing metallicity remains a challenge. A Schottky catalyst based on metal–semiconductor junction principles is presented. With metallic MoB, the introduction of n‐type semiconductive g‐C3N4 induces a vigorous charge transfer across the MoB/g‐C3N4 Schottky junction, and increases the local electron density in MoB surface, confirmed by multiple spectroscopic techniques. This Schottky catalyst exhibits a superior HER activity with a low Tafel slope of 46 mV dec−1 and a high exchange current density of 17 μA cm−2, which is far better than that of pristine MoB. First‐principle calculations reveal that the Schottky contact dramatically lowers the kinetic barriers of both proton adsorption and reduction coordinates, therefore benefiting surface hydrogen generation.
Supramolecular Polymerization Controlled through Kinetic Trapping
Authors: Chen Hao , Huang Zehuan , Wu Han , Xu Jiang‐Fei , Zhang Xi 
Published: November 2017

AbstractA method of controllable supramolecular polymerization through kinetic trapping is developed. To this end, two bifunctional monomers with cucurbit[7]uril (CB[7]) and adamantane end groups were synthesized. The CB[7]‐containing monomer was presaturated with a pH‐responsive competitive guest for kinetic control. Then, the kinetics of supramolecular polymerization of the two monomers was easily controlled through the modulation of pH. As a result, supramolecular polymerization was kinetically trapped at certain stages, and supramolecular polymers with different molecular weights were obtained. It is anticipated that this research will enrich the methods of controllable supramolecular polymerization.
Podophyllotoxin extraction from Linum usitatissimum plant and its anticancer activity against HT‐29, A‐549 and MDA‐MB‐231 cell lines with and without the presence of gold nanoparticles
Authors: Safarpoor Mohammad , Ghaedi Mehrorang , Yousefinejad Masoume , Javadian Hamedreza , Asfaram Arash , Ghasemi Zahra , Jaberi Hajar , Rahimi Daruosh 
Published: November 2017

In recent years, gold nanoparticles (Au‐NPs) have been taken into consideration in nanomedicine due to their excellent biocompatibility, chemical stability and promising optical properties. In this research, podophyllotoxin conjugated with gold nanoparticles (Au‐NPs‐POT) was synthesized and the conjugation of POT with Au‐NPs was confirmed using scanning electron microscopy, mass spectrometry and Fourier transform infrared spectroscopy. The anticancer effects of the product on preclinical models of lung, colon and breast cancers were investigated using MTT test. The analyses showed a direct dose–response relationship. It was found that higher concentrations of POT have more positive effects on the inhibition of cancer cell growth. At POT concentrations of 1, 2.5, 5, 7.5, 10, 15 and 20 ng ml−1, approximately 50% of the growth of colorectal, lung and breast cancer cell lines was inhibited, while similar results were obtained in the presence of 1, 2, 3, 4 and 5 μg ml−1 Au‐NPs‐POT. Au‐NPs‐POT exhibited the lowest cytotoxicity due to the presence of POT. The anticancer feature of Au‐NPs‐POT proved the potential to develop better anticancer therapeutics and to open new avenues for treatment of cancers.
Computational insight into asymmetric uranyl‐salophen coordinated with α, β‐unsaturated aldehydes and ketones
Authors: Lan Wen‐Bo , Wang Xiao‐Feng , He Li‐Ping , Meng Yan‐Bin , Li Jun , Qiu Bin , Nie Chang‐Ming 
Published: November 2017

The study of the catalytic activity and activation mechanism of asymmetric uranyl‐salophens with α, β‐unsaturated aldehydes or α, β‐unsaturated ketones, is a research hotspot. In this paper, the complexes of the uranyl–salophen(U‐S) modified by unilateral benzene, coordinated with cyclohexenone, cyclopentenone and acrolein, were investigated using density functional theory calculations at the level of B3LYP/6‐311G(d, p) basis set. The results showed that the uranyl‐salophen(U‐S) weakened the large π bond between C = C and C = O of the α, β‐unsaturated aldehydes and ketones, making the unsaturated aldehydes and ketones activated. In addition, the molecular‐recognition selectivity of the asymmetrical uranyl‐salophen for cyclohexenone and cyclopentenone were much higher than for acrolein.
Solid‐state single‐ion conducting comb‐like siloxane copolymer electrolyte with improved conductivity and electrochemical window for lithium batteries
Authors: Ren Chaoshi , Liu Mingzhu , Zhang Jiawen , Zhang Qinghua , Zhan Xiaoli , Chen Fengqiu 
Published: November 2017

ABSTRACTAchievement of high conductivity and electrochemical window at ambient temperature for an all‐solid polymer electrolyte used in lithium ion batteries is a challenge. Here, we report the synthesis and characterization of a novel solid‐state single‐ion electrolytes based on comb‐like siloxane copolymer with pendant lithium 4‐styrenesulfonyl (perfluorobutylsulfonyl) imide and poly(ethylene glycol). The highly delocalized anionic charges of SO2N(–)C4F9 have a weak association with lithium ions, resulting in the increase of mobile lithium ions number. The designed polymer electrolytes possess ultra‐low glass transition temperature in the range from −73 to −54 °C due to the special flexible polysiloxane. Promising electrochemical properties have been obtained, including a remarkably high conductivity of 3.7 × 10−5 S/cm and electrochemical window of 5.2 V (vs. Li+/Li) at room temperature. A high lithium ion transference number of 0.80, and good compatibility with anode were also observed. These prominent characteristics endow the polymer electrolyte a potential for the application in high safety lithium ion batteries. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45848.
Effects of aging on poly(1‐trimethylsilyl‐1‐propyne) membranes irradiated with vacuum ultraviolet radiation for gas separation
Authors: Yoshioka Tetsuro , Miyashita Yoshiki , Motoo Taichi , Saito Kentaro , Nagai Kazukiyo 
Published: November 2017

ABSTRACTIn this study, we investigated the effects of physical aging on the surface and gas‐transport properties of highly gas permeable poly(1‐trimethylsilyl‐1‐propyne) membranes irradiated with vacuum ultraviolet (VUV) radiation. VUV excimer lamp irradiation was performed on one side of the membrane for 6 or 60 min. The gas permeabilities for carbon dioxide (CO2) and nitrogen (N2) were determined through a volumetric measurement method at 23 °C. The gas permeabilities for CO2 and N2 increased temporarily at 7 days after 6 and 60 min of VUV irradiation of the membranes. The change in the gas permeability for N2 was more remarkable than that for CO2. These changes were related to the CO or SiOx ratio. The CO ratio was related to the gas permeability of the membranes VUV‐irradiated for 6 min, whereas the SiOx ratio was related to the gas permeability of the membranes VUV‐irradiated for 60 min. These changes affected the gas selectivities of the membranes. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45973.
Rheological and mechanical properties of thermoplastic polyurethane elastomer derived from CO2 copolymer diol
Authors: Xian Wenqi , Song Lina , Liu Baohua , Ding Hulan , Li Zhao , Cheng Mengping , Ma Le 
Published: November 2017

ABSTRACTCO2 copolymer diol‐based thermal polyurethane elastomers (PPC‐TPU) were prepared by the reaction of CO2 copolymer diol and methylene diphenyl diisocyanate and chain extender (ethylene glycol/1,4‐butanediol/1,6‐hexanediol) (EG/BDO/HG). The rheological and mechanical properties of PPC‐TPU were analyzed. The effects of shear rate, shear temperature, hard segment content, and variety of chain extender on the properties of PPC‐TPU were studied. The results showed that the apparent viscosity (η) of PPC‐TPU decreased with the increasing shear rate (τ), and the non‐Newtonian index (n) was less than 1. PPC‐TPU exhibited a typical character of pseudoplastic non‐Newtonian rheological behavior. The degradation during the processing was obviously inhibited by adding plasticizer and antioxidant. It was also discovered that the apparent viscosity varied with the content of hard segment and chain extender. Under the same temperature (185 °C) and shear rate (50 s−1), the apparent viscosity increased considerably with the raise of hard segment content, and the apparent viscosity and tensile strength of PPC‐TPU with EG as chain extender was the maximum. It can be seen that with the apparent shear rate increasing, the variation tendency of apparent shear stress levels off, and the nonlinear relationship of τ–γ curve tended to be obvious. PPC‐TPU exhibited a typical character of pseudoplastic non‐Newtonian rheological behavior. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45974.
Visible‐Light Photoactive, Highly Efficient Triplet Sensitizers Based on Iodinated Aza‐BODIPYs: Synthesis, Photophysics and Redox Properties
Authors: Gut Arkadiusz , Łapok Łukasz , Drelinkiewicz Dawid , Pędziński Tomasz , Marciniak Bronisław , Nowakowska Maria 
Published: November 2017

AbstractA series of novel iodinated NO2‐substituted aza‐BODIPYs have been synthesized and characterized. Highly desirable photophysical and photochemical properties were induced in NO2‐substituted aza‐BODIPYs by iodination of the pyrrole rings. In particular, high values of singlet oxygen quantum yields (ΦΔ) ranging from 0.79 to 0.85 were measured. The photooxygenation process proceeds via a Type II mechanism under the experimental conditions applied. The compounds studied exhibited an absorption band within the so‐called “therapeutic window”, with λmax located between 645 nm to 672 nm. They were non‐fluorescent at room temperature with excited singlet‐state lifetimes within the picosecond range as measured by femtosecond transient absorption. Nanosecond laser flash photolysis experiments revealed T1→Tn absorption spanning from ca. 400 nm to ca. 500 nm and allowed determination of the triplet‐state lifetimes. The estimated triplet lifetimes (τT) in deaerated acetonitrile ranged between 2.74 μs and 3.50 μs. As estimated by CV/DPV measurements, all iodinated aza‐BODIPYs studied exhibited one irreversible oxidation and two quasi‐reversible reductions processes. Estimation of the EHOMO gave the value of −6.06 to −6.26 eV while the ELUMO was found to be located at ca. −4.6 eV. Thermogravimetric (TGA) analysis revealed that iodinated aza‐BODIPYs were stable up to approximately 300 °C. All compounds studied exhibit high photostability in toluene solution.
Joint effects of prenatal air pollutant exposure and maternal folic acid supplementation on risk of autism spectrum disorder
Authors: Goodrich Amanda J. , Volk Heather E. , Tancredi Daniel J. , McConnell Rob , Lurmann Fred W. , Hansen Robin L. , Schmidt Rebecca J. 
Published: November 2017

Independent studies report that periconceptional folic acid (FA) may decrease the risk of autism spectrum disorder (ASD) while exposure to air pollution may increase ASD risk. We examined the joint effects of gestational FA and air pollution exposures in association with ASD. We studied 346 ASD cases and 260 typically developing controls from the CHARGE case‐control study. Self‐reported FA intake for each month of pregnancy was quantified. Estimates of exposure to near roadway air pollution (NRP) and criteria air pollutant measures were assigned based on maternal residential history. Among mothers with high FA intake (>800 μg) in the first pregnancy month, exposure to increasing levels of all air pollutants, except ozone, during the first trimester was associated with decreased ASD risk, while increased ASD risk was observed for the same pollutant among mothers with low FA intake (≤800 μg). This difference was statistically significant for NO2 (e.g., NO2 and low FA intake: OR = 1.53 (0.91, 2.56) vs NO2 and high FA intake: OR = 0.74 (0.46, 1.19), P‐interaction = 0.04). Mothers exposed to higher levels (≥ median) of any air pollutant during the first trimester of pregnancy and who reported low FA intake were at a higher ASD risk compared to mothers exposed to lower levels of that air pollutant and who reported high first month FA intake. Joint effects showed significant (alpha < 0.10) departures from expected interaction for NRP and NO2. Our results suggest that periconceptional FA intake may reduce ASD risk in those with high prenatal air pollution exposure. Further study is needed to replicate these findings in larger sample sizes and to understand mechanisms of this potential relationship.. Autism Res 2018, 11: 69–80. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryWe examined interactions between periconceptional folic acid (FA) and air pollution exposure on risk of ASD. Mothers exposed to higher levels of air pollution during the first trimester of pregnancy and who reported low supplemental FA intake during the first pregnancy month were at a higher ASD risk compared to mothers exposed to lower levels of air pollution and who reported high first month FA intake. Our results suggest that periconceptional FA intake may reduce ASD risk in those with high prenatal air pollution exposure.
Avatar‐based counselling for young people within school counselling. Qualitative analysis of client experience
Authors: van Rijn Biljana , Cooper Mick , Chryssafidou Evi 
Published: November 2017

AbstractBackgroundThis study is a qualitative analysis of clients’ experiences of a new avatar based counselling intervention, based on the ‘ProReal’ software (www.proreal.world). The intervention was piloted in eight secondary schools in the UK in 2016.AimsTwenty‐nine participants (53% of the full sample) were interviewed about their use of the software, experience of the intervention, process of change and views about its helpfulness.Materials and MethodsInterviews were semi‐structured and were analysed using thematic analysis.ResultsThe analysis shows that the intervention was potentially attractive to these clients, particularly those enthusiastic about digital software and clients who found visual communication helpful. The software provided additional opportunities for clients to communicate their inner worlds to the counsellor and supported the development of insight. Male clients, in particular, commented on its helpfulness.DiscussionThere is an indication that digital imagery supported the process of change in counselling and the development of meaning bridges: both internally and with the counsellor (Stiles, 2011; Stiles et al., 1990). However, the software could be experienced as an obstacle when clients wanted to talk about specific problems or ‘vent’ their feelings. All clients who reported that they did not find the software helpful were female. There were a number of suggestions about developing the software to increase opportunities for expression as well as appropriateness for clients from different minority ethnic backgrounds.ConclusionUse of digital software in counselling has a potential to enhance communication and support a process of change, particularly with male clients, those who find visual communication helpful, and clients enthusiastic about digital technology. Further research is needed to develop the intervention and compare it to the use of other creative media in counselling.
Phage Display on the Anti‐infective Target 1‐Deoxy‐d‐xylulose‐5‐phosphate Synthase Leads to an Acceptor–Substrate Competitive Peptidic Inhibitor
Authors: Marcozzi Alessio , Masini Tiziana , Zhu Di , Pesce Diego , Illarionov Boris , Fischer Markus , Herrmann Andreas , Hirsch Anna K. H. 
Published: November 2017

AbstractEnzymes of the 2‐C‐methyl‐d‐erythritol‐4‐phosphate pathway for the biosynthesis of isoprenoid precursors are validated drug targets. By performing phage display on 1‐deoxy‐d‐xylulose‐5‐phosphate synthase (DXS), which catalyzes the first step of this pathway, we discovered several peptide hits and recognized false‐positive hits. The enriched peptide binder P12 emerged as a substrate (d‐glyceraldehyde‐3‐phosphate)‐competitive inhibitor of Deinococcus radiodurans DXS. The results indicate possible overlap of the cofactor‐ and acceptor‐substrate‐binding pockets and provide inspiration for the design of inhibitors of DXS with a unique and novel mechanism of inhibition.
Improvement in the Thermostability of a β‐Amino Acid Converting ω‐Transaminase by Using FoldX
Authors: Buß Oliver , Muller Delphine , Jager Sven , Rudat Jens , Rabe Kersten S. 
Published: November 2017

Abstractω‐Transaminases (ω‐TAs) are important biocatalysts for the synthesis of active, chiral pharmaceutical ingredients containing amino groups, such as β‐amino acids, which are important in peptidomimetics and as building blocks for drugs. However, the application of ω‐TAs is limited by the availability and stability of enzymes with high conversion rates. One strategy for the synthesis and optical resolution of β‐phenylalanine and other important aromatic β‐amino acids is biotransformation by utilizing an ω‐transaminase from Variovorax paradoxus. We designed variants of this ω‐TA to gain higher process stability on the basis of predictions calculated by using the FoldX software. We herein report the first thermostabilization of a nonthermostable S‐selective ω‐TA by FoldX‐guided site‐directed mutagenesis. The melting point (Tm) of our best‐performing mutant was increased to 59.3 °C, an increase of 4.0 °C relative to the Tm value of the wild‐type enzyme, whereas the mutant fully retained its specific activity.
Magnetostructural Investigation of Orthogonal 1‐Aryl‐3‐Phenyl‐1,4‐Dihydrobenzo[e][1,2,4]triazin‐4‐yl Derivatives
Authors: Gardias Anita , Kaszyński Piotr , Obijalska Emilia , Trzybiński Damian , Domagała Sławomir , Woźniak Krzysztof , Szczytko Jacek 
Published: November 2017

Abstract3‐Phenyl‐1,4‐dihydrobenzo[e][1,2,4]triazinyl radicals with the N(1) position substituted with naphth‐2‐yl (1 b), naphth‐1‐yl (1 c), pyren‐1‐yl (1 d), anthracen‐9‐yl (1 e), 2‐trifluoromethylphenyl (1 f), 3‐trifluoromethylphenyl (1 g), and 2‐iodophenyl (1 h) were characterized by using single‐crystal X‐ray diffraction, variable‐temperature magnetic susceptibility, and DFT computational methods. The substituent at N(1) is essentially orthogonal to the heterocycle plane in 1 f and 1 h, and with a high torsion angle in 1 c and 1 d. Radicals 1 c and 1 h form unusual infinite chains with crisscrossing hetero‐co‐facial π–π interactions, whereas radical 1 d forms analogous homo‐co‐facial arrangements. Infinite chains of homo‐co‐facial π–π dimers are found in 1 b, 1 f and 1 g; in the latter the position of the CF3 group controls the slippage of the dimers in the chain. No π–π parallel arrangements were found in 1 e. Magnetic susceptibility measurements demonstrated strong antiferromagnetic interactions in 1 b (J=−264±4 cm−1) and 1 f (J=−134±1 cm−1), while weak intradimer ferromagnetic interactions were found in 1 g (J2=+21±1 and J1=−15±1 cm−1). Other derivatives exhibit typical weak antiferromagnetic exchange interactions in a range of −5 to −10 cm−1.
Self‐Assembled Nanomicelles as MRI Blood‐Pool Contrast Agent
Authors: Babič Andrej , Vorobiev Vassily , Xayaphoummine Céline , Lapicorey Gaëlle , Chauvin Anne‐Sophie , Helm Lothar , Allémann Eric 
Published: November 2017

AbstractGadolinium‐loaded nanomicelles show promise as future magnetic resonance imaging (MRI) contrast agents (CAs). Their increased size and high gadolinium (Gd) loading gives them an edge in proton relaxivity over smaller molecular Gd‐complexes. Their size and stealth properties are fundamental for their long blood residence time, opening the possibility for use as blood‐pool contrast agents. Using l‐tyrosine as a three‐functional scaffold we synthesized a nanostructure building block 8. The double C18 aliphatic chain on one side, Gd‐1,4,7,10‐tetraazacyclododecane‐1‐4‐7‐triacetic acid (Gd‐DO3A) with access to bulk water in the center and 2 kDa PEG on the hydrophilic side gave the amphiphilic properties required for the core–shell nanomicellar architecture. The self‐assembly into Gd‐loaded monodispersed 10–20 nm nanomicelles occurred spontaneously in water. These nanomicelles (Tyr‐MRI) display very high relaxivity at 29 mm−1 s−1 at low field strength and low cytotoxicity. Good contrast enhancement of the blood vessels and the heart together with prolonged circulation time in vivo, makes Tyr‐MRI an excellent candidate for a new supramolecular blood‐pool MRI CA.
Deltamides and Croconamides: Expanding the Range of Dual H‐bond Donors for Selective Anion Recognition
Authors: Zwicker Vincent E. , Yuen Karen K. Y. , Smith David G. , Ho Junming , Qin Lei , Turner Peter , Jolliffe Katrina A. 
Published: November 2017

AbstractDual H‐bond donors are widely used as recognition motifs in anion receptors. We report the synthesis of a library of dual H‐bond receptors, incorporating the deltic and croconic acid derivatives, termed deltamides and croconamides, respectively, and a comparison of their anion binding affinities (for monovalent species) and Brønsted acidities to those of the well‐established urea and squaramide dual H‐bond donor motifs. For dual H‐bonding cores with identical substituents, the trend in Brønsted acidity is croconamides>squaramides>deltamides>ureas, with the croconamides found to be 10–15 pKa units more acidic than the corresponding ureas. In contrast to the trends displayed by ureas, deltamides and squaramides, N,N′‐dialkyl croconamides displayed higher binding affinity to chloride than the N,N′‐diaryl derivatives, which was attributed to partial deprotonation of the N,N′‐diaryl derivatives at neutral pH. A number of differences in anion binding selectivity were observed upon comparison of the dual H‐bond cores. Whereas the squaramides display similar affinity for both chloride and acetate ions, the ureas have significantly higher affinity for acetate than chloride ions and the deltamides display higher affinity for dihydrogenphosphate ions than other oxoanions or halides. These inherent differences in binding affinity could be exploited in the design of anion receptors with improved ability to discriminate between monovalent anions.