bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hiyama cross‐coupling reaction using Pd(II) nanocatalyst immobilized on the surface of Fe3O4@SiO2
Authors: Karami Kazem , Jamshidian Nasrin , Nikazma Mohammad Mehdi , Hervés Pablo , Shahreza Amir Rezaei , Karami Ali 
Published: September 2017

We report a simple process for the synthesis of Fe3O4@SiO2/APTMS (APTMS = 3‐aminopropyltrimethoxysilane) core–shell nanocatalyst support. The new nanocatalyst was prepared by stabilization of Pd(cdha)2 (cdha = bis(2‐chloro‐3,4‐dihydroxyacetophenone)) on the surface of the Fe3O4@SiO2/APTMS support. The structure and composition of this catalyst were characterized using various techniques. An efficient method was developed for the synthesis of a wide variety of biaryl compounds via fluoride‐free Hiyama cross‐coupling reactions of aryl halides with arylsiloxane, with Fe3O4@SiO2/APTMS/Pd(cdha)2 as the catalyst under reaction conditions. This methodology can be performed at 100°C through a simple one‐pot operation using in situ generated palladium nanoparticles. High catalytic activity, quick separation of catalyst from products using an external magnetic field and use of water as green solvent are attributes of this protocol.
Fe3O4@SiO2@propyl‐ANDSA: A new catalyst for the synthesis of tetrazoloquinazolines
Authors: Ghorbani‐Vaghei Ramin , Alavinia Sedigheh , Sarmast Narges 
Published: September 2017

In this paper, a mild and green protocol has been developed for the synthesis of quinazoline derivatives. The catalytic activity of 7‐aminonaphthalene‐1,3‐disulfonic acid‐functionalized magnetic Fe3O4 nanoparticles (Fe3O4@SiO2@Propyl–ANDSA) was investigated in the one‐pot synthesis of new derivatives of tetrahydrotetrazolo[1,5‐a]quinazolines and tetrahydrobenzo[h]tetrazolo[5,1‐b]quinazolines from the reaction of aldehydes, 5‐aminotetrazole, and dimedone or 6‐methoxy‐3,4‐dihyronaphtalen‐1(2H)‐one at 100 °C in H2O/EtOH as the solvent. The catalyst was characterized before and after the organic reaction. Fe3O4@SiO2@Propyl–ANDSA showed remarkable advantages in comparison with previous methods. Advantages of the method presented here include easy purification, reusability of the catalyst, green and mild procedure, and synthesis of new derivatives in high yields within short reaction time.
Preparation of magnetically recyclable ZnFe2O4 nanoparticles by easy single‐step co‐precipitation method and their catalytic performance in the synthesis of 2‐aminothiophenes
Authors: Erfaninia N. , Tayebee R. , Foletto E.L. , Amini M.M. , Dusek M. , Zonoz F.M. 
Published: September 2017

In this work, a new synthetic route for the preparation of ZnFe2O4 nanoparticles through the chemical co‐precipitation using Fe2+ and Fe3+ ions in an alkaline solution was developed. The synthesized nanoparticles were characterized by XRD, FTIR, SEM, ICP‐MS, DRS, TGA, VSM and elemental analysis. Characterization results confirmed the formation of single ZnFe2O4 phase, with an average particle size of 40 nm and a high saturation magnetization of 34 emu g−1. The prepared material was employed as a catalyst for the synthesis of 2‐aminotiophene derivatives through the Gewald reaction. This thermally and chemically stable nanocatalyst is environmentally benign, economical and reusable which can be easily recovered using an external magnet. Therefore, it appears that this methodology can be simply extended for industrial purposes.
Electrospinning of polycaprolactone nanofibers using H2O as benign additive in polycaprolactone/glacial acetic acid solution
Authors: Li Wenchao , Shi Lei , Zhang Xianglin , Liu Kang , Ullah Ismat , Cheng Penghua 
Published: September 2017

ABSTRACTConsiderable efforts have been devoted to the production of polycaprolactone (PCL) nanofibrous structures by electrospinning. However, some toxic solvents have often been used to achieve bead‐free nanofibers. At present, a benign solvent such as glacial acetic acid (GAC) only leads to beaded or microscale fibers. Therefore a study is done to extend the electrospinnability of the PCL/GAC system by the addition of H2O. The solution properties of conductivity, viscosity, and surface tension were altered by the addition of H2O, especially increasing the conductivity and viscosity. These properties essential to electrospinning could remain stable for 6 h when the H2O content was less than or equal to 9 vol %. Then ultrafine PCL fibers with diameters from 188 to 200 nm, 10 times smaller than when dissolved in pure GAC, were electrospun from solutions of PCL with concentrations in the range of 17 to 20 wt % with H2O content at 9 vol %. Finally, the crystallinity and crystallite size of the resulting fibers were smaller than that of raw PCL pellets. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45578.
Poly(lactic acid) formulations with improved toughness by physical blending with thermoplastic starch
Authors: Ferri J.M. , Garcia‐Garcia D. , Carbonell‐Verdu A. , Fenollar O. , Balart R. 
Published: September 2017

ABSTRACTThis work focuses on poly(lactic acid) (PLA) formulations with improved toughness by physical blending with thermoplastic maize starch (TPS) plasticized with aliphatic–aromatic copolyester up to 30 wt %. A noticeable increase in toughness is observed, due to the finely dispersed spherical TPS domains in the PLA matrix. It is worth to note the remarkable increase in the elongation at break that changes from 7% (neat PLA) up to 21.5% for PLA with 30 wt % TPS. The impact‐absorbed energy is markedly improved from the relatively low values of neat PLA (1.6 J m−2) up to more than three times. Although TPS is less thermally stable than PLA due to its plasticizer content, in general, PLA/TPS blends offer good balanced thermal stability. The morphology reveals high immiscibility in PLA/TPS blends, with TPS‐rich domains with an average size of 1 μm, finely dispersed which, in turn, is responsible for the improved toughness. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45751.
Single Microbead‐Anchored Fluorescent Immunoassay (SMFIA): A Facile and Versatile Platform Allowing Simultaneous Detection of Multiple Antigens
Authors: Chen Desheng , Zhang Xiaobo , Zhu Liping , Liu Chenghui , Li Zhengping 
Published: September 2017

AbstractA new concept of single microbead (MB)‐anchored fluorescent immunoassay (SMFIA) is proposed with greatly improved sensitivity. In the SMFIA, a single MB is manipulated as the reaction carrier so that the target‐tethered fluorescent immunocomplexes will be highly concentrated on one MB. By monitoring the enriched fluorescence signal on the single MB through imaging, highly sensitive target quantification can be realized just by employing the most common sandwich immunoreactions without requirement of further signal amplification routes. The high sensitivity of the SMFIA can fully meet the demand of current medical diagnosis. Furthermore, we have further advanced a fluorescence‐encoding mechanism for the proposed SMFIA which allows the simultaneous detection of multiple antigens in a single reaction. Sharing the distinct advantages of simple operation, high sensitivity and multiplexed detection capability, the SMFIA provides a general platform for the detection of various biomarkers.
In situ biosensor for detection miRNA in living cells based on carbon nitride nanosheets with catalytic hairpin assembly amplification
Authors: Liao Xianjiu , Li Liqing , Pan Jianbin , Peng Tingting , Ge Bin , Tang Qianli 
Published: September 2017

AbstractIn this study, an ultrasensitive fluorescence turn‐on assay for in situ sensing of intracellular microRNA (miRNA) was developed utilizing a carbon nitride nanosheet (CNNS) and a catalytic hairpin assembly (CHA). The CHA showed favourable signal amplification for low‐level biomarkers, and CNNS was an excellent candidate as a fluorescence quencher and gene vector. Moreover, the hairpin DNA of CHA could be adsorbed onto the surface of CNNS. An enzyme‐free fluorescence biosensor for ultrasensitive sensing of intracellular miRNA in cells based on CHA and CNNS was designed. When faced with target miRNA, the fluorescence was recovered due to the miRNA, which could trigger cycling of CHA circuits, leading to the production of a marked enhanced fluorescence signal. Compared with traditional methods, the proposed method is convenient, with low cytotoxicity, and high specificity and ultrasensitivity. It has promising potential for detection low‐level biomarkers.
Development of an optical sensor for chlortetracycline detection based on the fluorescence quenching of l‐tryptophan
Authors: Zhang Hui , Chen Hongyun , Pan Shuang , Yang Huan , Yan Jingjing , Hu Xiaoli 
Published: September 2017

A simple and selective spectrofluorimetric method for the detection of chlortetracycline (CTC) was studied. In pH 7.4 buffer medium l‐tryptophan (l‐Trp), applied as the fluorescence probe, interacted with CTC resulting in fluorescence quenching of the probe. CTC was detected with maximum excitation and emission wavelengths at λex/λem = 275/350 nm. Notably, quenching of fluorescence intensities was positively proportional to the CTC concentration over the range of 0.65–30 μmol L−1 and the limit of detection was 0.2 μmol L−1. Effect of temperature shown in Stern−Volmer plots, absorption spectra and fluorescence lifetime determination, indicated that fluorescence quenching of l‐Trp by CTC was mainly by static quenching. The proposed study used practical samples analysis satisfactorily.
Double-blind randomized clinical trial of percutaneous endoscopic gastrostomy versus radiologically inserted gastrostomy in children
Authors: Singh R R , Nah S A , Roebuck D J , Eaton S , Pierro A , Curry J I , Barnacle A , Chippington S , Stuart S , Gibson C , Cross K M K , Stanwell J , Yardley I E , Kiely E M , De Coppi P 
Published: September 2017

Abstract

Background
The aim of this RCT was to determine whether radiologically inserted gastrostomy (RIG) in children is associated with more complications than percutaneous endoscopic gastrostomy (PEG).

Methods
Children at a single tertiary children's hospital requiring a primary gastrostomy were randomized to PEG or RIG. Patients were followed by assessors blinded to the insertion method. Complications were recorded, assigned a severity score, and analysed by zero-inflated Poisson regression analysis on an intention-to-treat basis, adjusting for length of follow-up.

Results
Over a 3-year period, 214 children were randomized (PEG, 107; RIG, 107), of whom 100 received PEG and 96 RIG. There was no significant difference in the number of complications between PEG and RIG groups (P = 0·875), or in the complication score: patients undergoing RIG had a 1·04 (95 per cent c.i. 0·89 to 1·21) times higher complication score than those who underwent PEG (P = 0·597). Only age had an independent significant effect on complication score, with older patients having a 0·97 (0·95 to 1·00) times lower complication score per year.

Conclusion
PEG and RIG are both safe methods of gastrostomy insertion with a low rate of major complications. Registration number: NCT01920438 (http://www.clinicaltrials.gov).
Catheter‐related right atrial thrombus in sickle cell disease
Authors: Zhao Chen , Sathya Bharath , Nadal Rios Rosa , Arai Andrew E. , Brofferio Alessandra , Thein Swee Lay , Ruhl A. Parker 
Published: September 2017

Key Clinical MessageCatheter‐related right atrial thrombus (CRAT) can occur in patients with sickle cell disease, particularly if additional risk factors for thrombosis are present. Cardiac MRI may differentiate thrombi from other types of atrial masses. Treatment should include anticoagulation and the timing of catheter removal should balance the potential risk of embolization.
Vanadium‐Catalyzed Deoxydehydration of Glycerol Without an External Reductant
Authors: Petersen Allan R. , Nielsen Lasse B. , Dethlefsen Johannes R. , Fristrup Peter 
Published: September 2017

AbstractA vanadium‐catalysed deoxydehydration (DODH) of neat glycerol has been developed. Cheap and readily available ammonium metavanadate (NH4VO3) affords higher yields of allyl alcohol than the well‐established catalyst methyltrioxorhenium. A study in which deuterium‐labelled glycerol was used was undertaken to further elucidate the dual role of glycerol as both an oxidant and reductant. This study led to the proposal of a metal‐catalysed DODH mechanism for the production of allyl alcohol and a deeper understanding of the formation of the byproducts acrolein and propanal.
Promoting Catalytic Oxygen Activation by Localized Surface Plasmon Resonance: Effect of Visible Light Pre‐treatment and Bimetallic Interactions
Authors: Wong Roong Jien , Tsounis Constantine , Scott Jason , Low Gary K.‐C. , Amal Rose 
Published: September 2017

AbstractVisible light pre‐treatment has been found to be capable of enhancing the catalytic oxygen activation on AuPt/TiO2 by up to seven times. Visible light pre‐treatment exploits the localized surface plasmon resonance effect of Au to generate free electrons, which are transferred to the Pt active sites. The electron transfer was evident from a change in Pt speciation observed from X‐ray photoelectron spectroscopy, showing the presence of PtO after visible light pre‐treatment. Photoluminescence spectroscopy was used to reveal the bimetallic synergistic enhancement, as indicated by an overall decrease in the charge recombination rate. Further examination revealed that a good bimetallic interaction is necessary to achieve the enhancement by visible light pre‐treatment. Weak bimetallic interaction, such as the occurrence of element segregation in the bimetallic alloy, inhibits electron transfer from the Au to the Pt and increases electron recombination rates, diminishing the degree to which visible light pre‐treatment improves catalytic performance.
Directed Growth of a Bimetallic MOF Membrane and the Derived NiCo Alloy@C/NixCo1‐xO/Ni Foam Composite as an Efficient Electrocatalyst for the Oxygen Evolution Reaction
Authors: Ping Dan , Feng Xiao , Zhang Jun , Geng Jianming , Dong Xinfa 
Published: September 2017

AbstractHierarchically structured bimetallic NiCo‐MOF/LDH/Ni foam (NiCo‐MOF/LDH/NF; MOF=metal−organic framework, LDH=layered double hydroxides) composites were successfully fabricated by means of the in situ growth of NiCo‐MOF on the NiCo LDH buffer‐layer‐modified NF surface. After carbonization, the derived NiCo alloy@C/NixCo1‐xO/NF hierarchical nanocomposite showed excellent electrocatalytic activity with respect to the oxygen evolution reaction (OER); specifically, it exhibited a very low overpotential of 300 mV at a current density of 100 mA cm−2. The outstanding OER activity of the composite may be attributed to the open structure of the nanocomposite, the formation of the highly dispersed CoNi alloy, and the synergistic interaction between CoNi@C and NixCo1‐xO. This work introduces a new strategy for constructing advanced hierarchically structured nanocomposites for diverse applications.
Quantitative Analysis of the Self‐Assembly Process of Hexagonal PtII Macrocyclic Complexes: Effect of the Solvent and the Components
Authors: Baba Ayako , Kojima Tatsuo , Hiraoka Shuichi 
Published: September 2017

AbstractThe self‐assembly process of three PtII‐linked hexagonal macrocycles consisting of dinuclear PtII complexes and organic ditopic ligands was investigated in polar and less polar solvents by a recently developed approach: quantitative analysis of the self‐assembly process (QASAP). In polar CD3NO2, for all the three macrocycles, an ML2 complex was the dominant intermediate during self‐assembly, as a result of high positive allosteric cooperativity for the ligand exchange on the PtII centers of the dinuclear PtII complexes. On the other hand, in less polar CD2Cl2, the self‐assembly process was affected by the components. For two of the three macrocycles, the chainlike oligomers that contain fewer metals and ligands than the corresponding macrocycles grew with time and the type of the chainlike intermediates formed correlated with the allostericity of the two binding sites in the organic ditopic ligands. In every case, no long oligomers containing more components than the macrocycles themselves were produced during the self‐assembly even though free rotation around single bonds in the chainlike oligomers allows them to adopt various conformations that do not facilitate the cyclization. This result suggests that electrostatic and/or steric factors besides rigidity of the components make the cyclization advantageous not only thermodynamically but also kinetically.
Rutile TiO2 Mesocrystals as Sulfur Host for High‐Performance Lithium–Sulfur Batteries
Authors: Sun Qingqing , Chen Kaixiang , Liu Yubin , Li Yafeng , Wei Mingdeng 
Published: September 2017

AbstractAlthough lithium–sulfur (Li–S) batteries are among the most promising rechargeable batteries in the field of energy‐storage devices, their poor cycling performance restricts their potential applications. Polar materials can improve the cycling stability owing to their inherent strong chemical interaction with polysulfides. Herein, novel rutile TiO2 mesocrystals (RTMs) are employed as the host for sulfur in Li–S batteries; the RTMs display a stable cycling performance with a capacity retention of 64 % and a small average capacity decay rate of 0.12 % per cycle over 300 cycles at 1 C rate. The good electrochemical properties are attributed to the interior ordered nanopores of the RTMs, which can effectively limit the dissolution of polysulfides, and the ultrafine nanowires in RTMs, which shorten the path for lithium‐ion transport effectively.
Pd/C‐Catalyzed Aminocarbonylation of Aryl Iodides with Anthranils in Water Using Mo(CO)6 as the CO Source
Authors: Wang Zechao , Yin Zhiping , Wu Xiao‐Feng 
Published: September 2017

AbstractA convenient procedure for the synthesis of N‐(2‐carbonylaryl)benzamides has been developed. Through Pd/C‐catalyzed aminocarbonylation of anthranils with various hindered and functionalized aryl iodides, the desired amides were afforded in moderate to good yields. The protocol is advantageous due to the recyclable Pd/C catalyst, safe Mo(CO)6 as the solid CO source, and environmentally benign water as solvent. No inert atmosphere protection is needed.
Quadruple Stimuli‐Responsive Mechanized Silica Nanoparticles: A Promising Multifunctional Nanomaterial for Diverse Applications
Authors: Ding ChenDi , Tong Ling , Fu JiaJun 
Published: September 2017

AbstractNovel quadruple stimuli‐responsive mechanized silica nanoparticles were constructed by installation of supramolecular nanovalves onto the exterior surface of mesoporous silica nanoparticles. The release of cargo molecules is triggered by acid/Zn2+/alkali/reduction potential stimuli. This has potential application in the development of drug delivery systems or construction of smart anticorrosion coatings.
Hydrogen Chemisorption on Singly Vanadium‐Doped Aluminum Clusters
Authors: Vanbuel Jan , Fernández Eva M. , Ferrari Piero , Gewinner Sandy , Schöllkopf Wieland , Balbás Luis C. , Fielicke André , Janssens Ewald 
Published: September 2017

AbstractThe effect of vanadium doping on the hydrogen adsorption capacity of aluminum clusters (Aln+, n=2–18) is studied experimentally by mass spectrometry and infrared multiple photon dissociation (IRMPD) spectroscopy. We find that vanadium doping enhances the reactivity of the clusters towards hydrogen, albeit in a size‐dependent way. IRMPD spectra, which provide a fingerprint of the hydrogen binding geometry, show that H2 dissociates upon adsorption. Density functional theory (DFT) calculations for the smaller AlnV+ (n=2–8,10) clusters are in good agreement with the observed reactivity pattern and underline the importance of activation barriers in the chemisorption process. Orbital analysis shows that the activation barriers are due to an unfavorable overlap between cluster and hydrogen orbitals.
Development and characterization of pine bark with enhanced capacity for uptaking Cr(III) from aqueous solutions
Authors: Arim Aline L. , Cecílio Daniela F. M. , Quina Margarida J. , Gando‐Ferreira Licínio M. 
Published: September 2017

AbstractThis work aims for the development and characterization of a new biosorbent with enhanced capacity for recovery of Cr(III) from aqueous solutions. The adsorbent was developed by chemical modification of pine bark (Pinus pinaster) (PB). Initially, several chemical agents (HCl, H2SO4, HNO3, H3PO4, citric acid, acetic acid, NaOH) were tested, but the best results were obtained with NaOH. The adsorbent developed was characterized regarding chemical composition and thermal behaviour before and after chemical modification. Scanning electron microscopy coupled with energy dispersive spectroscopy (SEM‐EDS) showed the morphology and the most relevant elements on the surface before and after adsorption of Cr(III). Fourier transform infrared spectroscopy (FTIR) revealed the important role of carboxylate groups in Cr(III) uptake. The adsorption process was studied under different conditions, namely for testing the particle size (in the ranges from 0.088 to 0.149 and 0.250 to 0.595 mm). The equilibrium isotherms showed that Cr(III) adsorption is strongly dependent on particle size. According to the Langmuir model, the maximum adsorption capacity of Cr(III) increased from 17.15 to 31.40 mg/g as the particle range decreased. The experimental Cr(III) removal efficiencies as a function of the adsorbent dosage were well predicted by the mass balance equation for the batch adsorption process coupled with the equilibrium isotherm.
Microfluidic Generation of Bioinspired Spindle‐knotted Graphene Microfibers for Oil Absorption
Authors: Wu Ziqian , Wang Jie , Zhao Ze , Yu Yunru , Shang Luoran , Zhao Yuanjin 
Published: September 2017

AbstractGraphene materials have a demonstrated value in water treatment. Efforts to promote these materials are focused on the generation of functional graphene adsorbents for effectively removing contaminants from water. Here, inspired by the conformation of spider silks, we present a novel graphene microfiber material with spindle‐knotted microstructures by using a microfluidic emulsification and spinning collaborative technology. The size and spacing of the spindle‐knots were highly controllable by adjusting the flow rates of microfluidics during the generation process of the microfibers. The generated microfibers could adsorb oil from a water‐oil mixed environment due to their hydrophobic surface chemistry. Because of the surface energy curvature gradient and the difference in Laplace pressure, the collected oil tended to form droplets and move from joints between the spindle‐knots to the knots. In addition, by encapsulating additional functional elements, such as magnetic nanoparticles, the graphene microfiber with the ability to control and facilitate the collection of oily contaminants can also be achieved. These features greatly prove the promising values of the spindle‐knotted graphene microfibers in the protection of the environment.
An extensible two‐phase high voltage‐boosting converter with automatic current balance
Authors: Hwu K.I. , Jiang W.Z. , Wu P.Y. 
Published: September 2017

SummaryIn this study, an extensible 2‐phase interleaved high step‐up converter with automatic current balance is presented. This converter uses coupled inductors and energy‐transferring capacitors to improve the voltage gain of the traditional 2‐phase interleaved boost converter as well as employs these energy transferring capacitors to do automatic current balance. Furthermore, the voltage gain can be enhanced not only by adjusting the turns ratio but also by increasing the numbers of phases, diodes, and energy‐transferring capacitors. Therefore, it can be used in high input current and high step‐up voltage applications. In this paper, the basic operating principles of the proposed converter are described and analyzed, and finally, its effectiveness is demonstrated by experiment. In addition, the field‐programmable gate array, named EP13T100C8N and manufactured by Altera Co, is used as a control kernel, and an experimental prototype, with input voltage of 12 V, output voltage of 200 V, and rated output power of 200 W, is given to provide the effectiveness of the proposed converter.