bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simple preparation and characterization of molecularly imprinted nylon 6 nanofibers for the extraction of bisphenol A from wastewater
Authors: Ardekani Razieh , Borhani Sedigheh , Rezaei Behzad 
Published: October 2018

ABSTRACTNylon 6 nanofibers incorporated with molecularly imprinted polymers (MIPs) were successfully fabricated by electrospinning with fiber diameters in the range 80–145 nm. Then, they were used as a new material for the extraction of selected bisphenol A (BPA) in water samples. Field emission scanning electron microscopy images revealed that the nanofibers had a smooth morphology with a good incorporation of MIPs. The Fourier transform infrared and energy‐dispersive X‐ray spectroscopy results also confirmed the formation of the MIPs in the nanofibers. Furthermore, Raman spectroscopy showed that the crystalline structure of the pristine nylon 6 nanofiber was a kind of α form, and the incorporation of MIPs led to a γ‐form structure in the nanofibers; this proved the interactions between nylon 6 and the MIPs. Adsorption studies also confirmed that the adsorption efficiency of BPA onto the molecularly imprinted polymer nanofibers (MIP‐NFs; 83.5%) was much greater than that onto nonimprinted polymer nanofibers (NIP‐NFs; 36.8%). Also, the imprinting factor was 3.4; this strongly implied the successful formation of molecularly imprinted cavities on the MIP‐NFs with a strong affinity to BPA. The maximum adsorption capacity of the MIP‐NFs was 103.8 mg/g. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47112.
Synthesis and characterization of heterocyclic core‐based polybenzoxazine matrices
Authors: Selvi M. , Devaraju S. , Vengatesan M. R. , Alagar M. 
Published: October 2018

ABSTRACTIn the present work, four types of heterocyclic core‐based polybenzoxazine matrices (HC‐PBZ) developed based on pyridine, thiophene, and thiazole and their molecular structure, thermal, flame‐retardant and luminescent properties were studied and discussed. The heterocyclic core‐based benzoxazine monomers (HC‐BZ) were synthesized using two types of phenols (phenol, and 4‐hydroxyphenylacetonitrile), and two types of heterocyclic diamines [2,6‐Bis‐(4‐aminophenyl)‐4‐thiophen‐2‐yl‐pyridine (BATP) and 4‐(2‐methylthiazol‐5‐yl)‐2,6‐bis‐(4‐aminophenyl)‐pyridine (BAMTP)] with formaldehyde through Mannich reaction. The structure of the four HC‐BZ monomers was confirmed by various spectral analysis such as Fourier‐transform infrared spectroscopy (FTIR), and Nuclear magnetic resonance spectroscopy (1HNMR and13CNMR). All the four HC‐BZ monomers have the maximum range of curing temperature (Tp) between 252 and 267 °C. Data resulted from the thermal studies indicate that the HC‐PBZ exhibits betterTg,thermal stability and flame‐retardant properties. Among the four HC‐PBZ systems the thiazole based system possesses the higher value ofTgof 268 °C and thermal stability when compared to those of other matrices. It was also observed that the HC‐BZ monomers and HC‐PBZ polymers exhibit a photoluminescent (PL) emission range between 441–445 and 414–417 nm, respectively. Overall, it seems that the thiazole and thiophene based HC‐PBZ can be considered as competitive materials for luminescent applications with high thermal and flame‐retardant properties. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 47134.
Enzyme‐mediated transglycosylation of rutinose (6‐O‐α‐l‐rhamnosyl‐d‐glucose) to phenolic compounds by a diglycosidase from Acremonium sp. DSM 24697
Authors: Mazzaferro Laura S. , Weiz Gisela , Braun Lucas , Kotik Michael , Pelantová Helena , Křen Vladimír , Breccia Javier D. 
Published: October 2018

AbstractThe structure of the carbohydrate moiety of a natural phenolic glycoside can have a significant effect on the molecular interactions and physicochemical and pharmacokinetic properties of the entire compound, which may include anti‐inflammatory and anticancer activities. The enzyme 6‐O‐α‐rhamnosyl‐β‐glucosidase (EC 3.2.1.168) has the capacity to transfer the rutinosyl moiety (6‐O‐α‐l‐rhamnopyranosyl‐β‐d‐glucopyranose) from 7‐O‐rutinosylated flavonoids to hydroxylated organic compounds. This transglycosylation reaction was optimized using hydroquinone (HQ) and hesperidin as rutinose acceptor and donor, respectively. Since HQ undergoes oxidation in a neutral to alkaline aqueous environment, the transglycosylation process was carried out at pH values ≤6.0. The structure of 4‐hydroxyphenyl‐β‐rutinoside was confirmed by NMR, that is, a single glycosylated product with a free hydroxyl group was formed. The highest yield of 4‐hydroxyphenyl‐β‐rutinoside (38%, regarding hesperidin) was achieved in a 2‐h process at pH 5.0 and 30 °C, with 36 mM OH‐acceptor and 5% (v/v) cosolvent. Under the same conditions, the enzyme synthesized glycoconjugates of various phenolic compounds (phloroglucinol, resorcinol, pyrogallol, catechol), with yields between 12% and 28% and an apparent direct linear relationship between the yield and the pKa value of the aglycon. This work is a contribution to the development of convenient and sustainable processes for the glycosylation of small phenolic compounds.
Die Verwandtschaft der europäischen Strauchweiden
Authors: Wagner Natascha 
Published: October 2018

ZusammenfassungDie Beziehungen der europäischen Strauchweiden (Gattung Salix, Untergattungen Chamaetia und Vetrix) waren bislang völlig unklar. Im Gegensatzu zu bisherigen molekularen Methoden, die zu wenig Informationen lieferten, konnten mithilfe des modernen DNA‐Sequenzierverfahrens, dem Restriction site Associated DNA sequencing (RAD sequencing), tausende informative Positionen des Genoms detektiert werden.Auf Basis dieser Daten konnte erstmals herausgefunden werden, dass die einzelnen beschriebenen Arten gut unterstützt werden, aber der traditionellen taxonomischen Eingruppierung aller Zwergweiden in eine gemeinsame Untergattung mithilfe der molekularen Daten klar widersprochen wird. Zwergsträucher sind offensichtlich als Anpassung an arktisch‐alpine Lebensräume mehrfach unabhängig voneinander entstanden.
Alles Zucker – oder was?
Authors: Bickel Susanne 
Published: October 2018

ZusammenfassungDas Disaccharid Saccharose wird im Pflanzenreich nur in Ausnahmefällen gespeichert, z. B. in der Zuckerrübe und im Zuckerrohr. Neben diesen Weltwirtschaftspflanzen gibt es noch eine Reihe anderer Pflanzen, aus denen Zucker (Saccharose) isoliert werden kann, der häufig nur regional verwendet wird. Obgleich schon die Muttermilch durch ihren hohen Laktosegehalt süß ist, und süße Beeren und Früchte uns ihre Genießbarkeit signalisieren, sind mit Haushaltszucker gesüßte Speisen heute als Dickmacher und Krankmacher verschrien.
Cyano Modification on Uridine Decreases Base‐Pairing Stability and Specificity through Neighboring Disruption in RNA Duplex
Authors: Mao Song , Ranganathan Srivathsan V. , Tsai Hsu‐Chun , Haruehanroengra Phensinee , Shen Fusheng , Valsangkar Vibhav A. , Han Bo , Hassan Abdalla E. A. , Chen Alan , Sheng Jia 
Published: October 2018

Abstract5‐Cyanomethyluridine (cnm5U) and 5‐cyanouridine (cn5U), the two uridine analogues, were synthesized and incorporated into RNA oligonucleotides. Base‐pairing stability and specificity studies in RNA duplexes indicated that cnm5U slightly decreased the stability of the duplex but retained the base‐pairing preference. In contrast, cn5U dramatically decreased both base‐pairing stability and specificity between U:A and other noncanonical U:G, U:U, and U:C pairs. In addition, the cn5U:G pair was found to be stronger than the cn5U:A pair and the other mismatched pairs in the context of a RNA duplex; this implied that cn5U might slightly prefer to recognize G over A. Our mechanistic studies by molecular simulations showed that the cn5U modification did not directly affect the base pairing of the parent nucleotide; instead, it weakened the neighboring base pair in the 5′ side of the modification in the RNA duplexes. Consistent with the simulation data, replacing the Watson–Crick A:U pair to a mismatched C:U pair in the 5′‐neighboring site did not affect the overall stability of the duplex. Our work reveals the significance of the electron‐withdrawing cyano group in natural tRNA systems and provides two novel building blocks for constructing RNA‐based therapeutics.
Room‐Temperature Activation of Molecular Oxygen Over a Metal‐Free Triazine‐Decorated sp2‐Carbon Framework for Green Synthesis
Authors: Lv Li‐Bing , Yang Shi‐Ze , Feng Wei‐Jie , Ke Wen‐Yu , Zhang Bing , Jiang Zhi‐Dong , Wang Hong‐Hui , Su Juan , Li Xin‐Hao , Chen Jie‐Sheng 
Published: October 2018

AbstractAdditive‐free activation of oxygen molecules under ambient conditions has been a great challenge for the green organic synthesis. To make it happen, the design of highly efficient catalyst is the key to make it happen. In this work, we report a simple method to prepare an atomic‐scale carbocatalyst via decorating sp2‐carbon framework with triazine (TA−G), which can activate molecular oxygen for highly efficient organic synthesis. Both theoretical and experimental results reveal that TA−G has a Fermi level lied in the middle of the oxygen 2p antibonding orbital of the absorbed O2 to weaken the O−O bond for room‐temperature and additive‐free activation of oxygen molecules.
Supported Polyhedral Oligomeric Silsesquioxane‐Based (POSS) Materials as Highly Active Organocatalysts for the Conversion of CO2
Authors: Calabrese Carla , Liotta Leonarda F. , Giacalone Francesco , Gruttadauria Michelangelo , Aprile Carmela 
Published: October 2018

AbstractVery high turnover numbers (TON) and productivity values up to 7875 and 740 respectively have been obtained for the conversion of CO2into cyclic carbonates by using hybrid materials based on imidazolium modified polyhedral oligomeric silsesquioxanes (POSS‐Imi) grafted on amorphous silica (SiO2) and mesostructured SBA‐15. The heterogeneous organocatalysts were easily preparedviaa straightforward synthetic procedure allowing to generate high local concentration spots of imidazolium active sites surrounding the POSS core. This synthetic procedure is also a promising approach for the design of a wide library of hybrid functional materials. The materials do not possess other co‐catalytic species with Lewis or Brønsted acid functionalities which still represents a challenging aspect for the outcome of the process. The recyclability of the catalysts was successfully verified for four consecutive runs. The catalytic versatility was proved with a wide range of epoxides and with the most challenging oxetane on large scale (105–210 mmol) showing higher performances in comparison with other unmodified imidazolium‐based catalytic systems. The new hybrids based on supported POSS nanostructures allowed the sustainable conversion of carbon dioxide under solvents‐ and metal‐free reaction conditions with a full selectivity toward cyclic carbonates.
Constructing Successive Active Sites for Metal‐free Electrocatalyst with Boosted Electrocatalytic Activities Toward Hydrogen Evolution and Oxygen Reduction Reactions
Authors: Zhang Quan , Luo Fang , Ling Ying , Guo Long , Qu Konggang , Hu Hao , Yang Zehui , Cai Weiwei , Cheng Hansong 
Published: October 2018

AbstractAs well known, heteroatom doped carbon material served as metal‐free electrocatalyst for hydrogen evolution (HER) and oxygen reduction reactions (ORR) particularly relies on the heteroatom doping level. Here, we report a 3D porous nitrogen doped carbon (PNC) electrocatalyst with superior HER and ORR electrocatalytic activities derived from the calcination of the discarded cigarette butt and dicyandiamide possessing a high nitrogen content (20 at%). PNC electrocatalyst only demands 143 mV versus RHE to achieve 10 mA cm−2 ascribed to the high nitrogen percentile in PNC electrocatalyst favorable for constructing successive active centers contributing to efficiently catalyzing HER. Ignorable degradation in HER activity observed after 10000 potential cycles as well as undetectable decay in HER performance recorded after 12 h operation indicate high stability of PNC electrocatalyst. Meanwhile, half‐wave potential of PNC electrocatalyst reaches 0.81 V versus RHE in 1 M KOH electrolyte. Additionally, stable ORR activity attained after 1000 potential cycles is indicative of high stability. A comparably high zinc‐air battery performance with maximum power density of 66 mW cm−2 is achieved by PNC electrocatalyst. This study highlights the importance of nitrogen doping level in metal‐free electrocatalyst for boosting HER and ORR activities.
Switching of Monomer Fluorescence, Charge‐Transfer Fluorescence, and Room‐Temperature Phosphorescence Induced by Aromatic Guest Inclusion in a Supramolecular Host
Authors: Ono Toshikazu , Taema Ai , Goto Aiko , Hisaeda Yoshio 
Published: October 2018

AbstractCrystal engineering of three‐component crystals with guest‐dependent photoluminescence switching, including (i) crystallization‐induced emission enhancement, (ii) intermolecular charge‐transfer emission, and (iii) room‐temperature phosphorescence under ultraviolet irradiation, was demonstrated. This strategy was based on the confinement of aromatic guests in a supramolecular host (denoted as EBPDI‐TPFB) composed of 5,5′‐(ethyne‐1,2‐diyl)bis(2‐pyridin‐3‐yl‐isoindoline‐1,3‐dione (EBPDI) with two tris(pentafluorophenyl)borane (TPFB) molecules linked by B−N dative bonds that acted as Lewis pairs. The single‐crystal X‐ray structures of complexes with eight different guests were collected, revealing that the size and/or shape of the supramolecular host EBPDI‐TPFB was modulated by the included guest molecules. The excellent guest inclusion ability of EBPDI‐TPFB allowed systematic photoluminescence regulation of the complexes, which exhibited multicolor emissions in the crystalline state. Photoluminescence switching characteristics of the complexes were observed upon removing the guests or mechanical grinding of the crystals. These results indicated that using the host–guest chemistry of multicomponent crystals not only facilitates crystallization, but also can reveal hidden optical functions by combining molecules of interest, which should contribute to the fields of physical chemistry and materials science.
Electrochemical Synthesis of 5‐Aryl‐phenanthridin‐6‐one by Dehydrogenative N,C Bond Formation
Authors: Kehl Anton , Breising Valentina M. , Schollmeyer Dieter , Waldvogel Siegfried R. 
Published: October 2018

AbstractCurrently, the general synthesis of 5‐aryl‐phenanthridin‐6‐ones relies on the involvement of metal catalysis. Despite the urgent demand for green alternatives, avoiding synthetic routes that require transition metals for key roles is still challenging. Electrochemical efforts employing a constant potential protocol in divided cells revealed a possible alternative to the catalytic approach. A constant current protocol, undivided cells, and a remarkably low supporting electrolyte concentration enable a novel access to N‐aryl‐phenanthridin‐6‐ones by anodic N,C bond formation using directly generated amidyl radicals. Easy accessible starting materials, a broad scope of applicable functional groups, good yields, and a very simple set‐up are the benefits of this sustainable method.
Exploring Rigid and Flexible Core Trivalent Sialosides for Influenza Virus Inhibition
Authors: Kiran Pallavi , Bhatia Sumati , Lauster Daniel , Aleksić Stevan , Fleck Carsten , Peric Natalija , Maison Wolfgang , Liese Susanne , Keller Bettina G. , Herrmann Andreas , Haag Rainer 
Published: October 2018

AbstractHerein, the chemical synthesis and binding analysis of functionalizable rigid and flexible core trivalent sialosides bearing oligoethylene glycol (OEG) spacers interacting with spike proteins of influenza A virus (IAV) X31 is described. Although the flexible Tris‐based trivalent sialosides achieved micromolar binding constants, a trivalent binder based on a rigid adamantane core dominated flexible tripodal compounds with micromolar binding and hemagglutination inhibition constants. Simulation studies indicated increased conformational penalties for long OEG spacers. Using a systematic approach with molecular modeling and simulations as well as biophysical analysis, these findings emphasize on the importance of the scaffold rigidity and the challenges associated with the spacer length optimization.
Rehospitalizations for complications and mortality following pacemaker implantation: A retrospective cohort study in an older population
Authors: Gillam Marianne H. , Pratt Nicole L. , Inacio Maria C. S. , Shakib Sepehr , Sanders Prashanthan , Lau Dennis H. , Roughead Elizabeth E. 
Published: October 2018

IntroductionA large number of older people receive pacemakers each year but broad population‐based studies that describe complications following pacemaker implantation in this population are lacking.MethodsWe conducted a retrospective cohort study using data from the Australian Government Department of Veterans' Affairs database. The cohort consisted of patients who received a pacemaker from 2005 to 2014. The outcomes were subsequent rehospitalizations for infections, procedure‐related complications, thromboembolism, cardiovascular events (heart failure, myocardial infarction, and atrial fibrillation), and reoperation of pacemaker, and mortality.ResultsThere were 10 883 pacemakers recipients, the median age was 86 years (interquartile range 83‐89), 61% were males, and 74% received a dual‐chamber pacemaker. Within 90 days postdischarge, rehospitalizations were occasioned by pacemaker infection in 0.5%, device‐related complications in 1.5%, cerebral infarction in 0.7%, and heart failure in 6% of single‐chamber pacemaker recipients. In dual‐chamber pacemaker recipients rehospitalizations were occasioned by pacemaker infection in 0.4%, septicemia in 0.4%, device‐related complications in 1.2%, cerebral infarction in 0.3%, and heart failure in 3%. Rehospitalizations for pacemaker adjustment occurred in 1.5% of patients. The 90‐day postdischarge mortality was 5% and 3% in patients with single‐ and dual‐chamber pacemaker, respectively.ConclusionRehospitalizations for infection, procedure‐related complications, or thromboembolism occurred in 1% to 2% of patients within 90 days postdischarge, while 10% of single chamber and 7% of dual‐chamber recipients experienced a rehospitalization for a cardiovascular event.
Large‐Size Transparent Wood for Energy‐Saving Building Applications
Authors: Wang Xuan , Zhan Tianyi , Liu Yan , Shi Jiangtao , Pan Biao , Zhang Yaoli , Cai Liping , Shi Sheldon Q. 
Published: October 2018

AbstractAs an energy‐saving building material, transparent wood (TW) is highly attractive because of the advantages of high optical transmittance, excellent mechanical properties, and good thermal insulation. However, the current research is limited to fabricating small‐size samples in the laboratory because thick or large‐size transparent wood is almost impossible to be achieved. A method that can easily and efficiently produce transparent wood with any size and any thickness is desirable for practical applications. Transparent wood made from wood fibers as a substrate allows the cell walls to bind more tightly to the impregnated polymer, resulting in high light transmittance. Compared with wood prepared by using previously reported approaches, the transparent wood prepared by this new method not only retains the same advantages but also has higher preparation efficiency and is suitable for large‐scale production. Under a simulated real environment, the retainability of indoor temperature by a sample house utilizing the transparent wood reveals excellent thermal insulation of the fiber‐based transparent wood owing to its low thermal conductivity, showing significant benefits in saving thermal energy.
In situ and Operando Tracking of Microstructure and Volume Evolution of Silicon Electrodes by using Synchrotron X‐ray Imaging
Authors: Dong Kang , Markötter Henning , Sun Fu , Hilger André , Kardjilov Nikolay , Banhart John , Manke Ingo 
Published: October 2018

AbstractThe internal microstructure of a silicon electrode in a lithium ion battery was visualized by operando synchrotron X‐ray radioscopy during battery cycling. The silicon particles were found to change their sizes upon lithiation and delithiation and the changes could be quantified. It was found that volume change of a particle is related to its initial size and is also largely determined by the changing surrounding electron‐conductive network and internal interface chemical environment (e.g., electrolyte migration, solid–electrolyte interphase propagation) within fractured particles. Moreover, an expansion prolongation phenomenon was discovered whereby some particles continue expanding even after switching the battery current direction and shrinkage would be expected, which is explained by assuming different expansion characteristics of particle cores and outer regions. The study provides new basic insights into processes inside Si particles during lithiation and delithiation and also demonstrates the unique possibilities of operando synchrotron X‐ray imaging for studying degradation mechanisms in battery materials.
Power maximization from resonant electromagnetic vibration harvesters feeding bridge rectifiers
Authors: Costanzo Luigi , Lo Schiavo Alessandro , Vitelli Massimo 
Published: October 2018

SummaryIn this paper, it is shown that, for resonant electromagnetic vibration energy harvesters (REVEH) feeding diode bridge rectifiers, it is possible to quantify how close the ideal load condition is to the actual load condition. For this purpose, a new figure of merit, the REVEH exploitation factor (REF), is introduced. The higher the REF, the higher the REVEH exploitation. Moreover, by using the REF, a suitable technique for increasing the extracted power in a frequency region of interest is investigated. This is the frequency region where a significant energy content of the input vibrations is present. The investigated technique is based on the proper insertion of additional non‐dissipative components (capacitors or inductors) between the REVEH coil and the bridge rectifier. Experimental results confirm the validity of the theoretical analysis.