bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immobilization of [MoO2(acac)2] on surface of hydroxyapatite nanoparticles: A heterogeneous and reusable catalyst for olefin epoxidation reactions
Authors: Ghanbari Resketi Farzane , Salehi Samie , Bahramian Bahram , Mirzaee Mahdi 
Published: December 2018

AbstractA new heterogeneous catalyst was prepared by grafting [MoO2(acac)2] on the hydroxyapatite (HAP) nanoparticle surfaces. The resulting catalyst, [MoO2(acac)]@HAP, was characterized by the powder X‐ray diffraction, FT‐IR spectroscopy, inductively coupled plasma/atomic emission spectroscopy, field emission scanning electron microscopy, energy‐dispersive X‐ray analysis, thermogravimetery analysis, and transmission electron microscopy techniques. The results obtained confirmed that the catalyst could be successfully used for the efficient epoxidation of olefins with tert‐butyl hydrogen peroxide in 1,2‐dichloroethane as the solvent. This heterogeneous catalyst could be reused for several times without a significant loss in its catalytic activity and with no significant reduction in the reaction yield. This novel material showed a great catalytic performance, and the reactions carried out using this catalyst showed a good‐to‐excellent yield, high purity of the desired products, and a short reaction time.
Carbocation stability as predictor for electrophilic addition of HCl to chlorinated ethenes and propenes in the gas phase
Authors: Zahl Maria G. , Sæthre Leif J. , Thomas T. Darrah , Børve Knut J. 
Published: December 2018

AbstractElectrophilic addition of halo acids to alkenes is commonly discussed in terms of the stability of the corresponding carbocation intermediate. In solution, this may be rationalized by reference to Hammond's postulate. The corresponding gas‐phase reaction takes place via a concerted mechanism without the formation of a cationic intermediate. Still, the series ethene, propene, and 2‐methylpropene show excellent correlation between proton affinities (PA) and gas‐phase activation energies for the addition of halo acids, with the activation energy decreasing linearly with increasing PA. Thus, PA presents itself as a potential predictor of reactivity also in the gas phase. To explore this possibility, we have performed high‐level calculations of cation stability (as reflected in PA) and activation energy for addition of HCl (Ea) for 12 chlorinated ethenes and propenes. Contrary to the hypothesis, for the present set of substrates, the correlation between PA and Ea is weak, and moreover, for subsets such as the series ethene, 1,2‐dichloroethene, and tetrachloroethene, Ea increases with increasing PA. An alternative approach of correlating Ea to carbon 1s ionization energies rather than PA shows moderately higher correlation overall and much better correlation within subsets of compounds that share the same number of chlorines attached to the carbon subject to electrophilic attack/core ionization.
Zinc Cobalt Sulfide Microspheres as a High‐Performance Electrode Material for Supercapacitors
Authors: Gao Xueyan , Chang Qin , Hong Juan , Long Dayang , Jin Guizhen , Xiao Xuxian 
Published: December 2018

AbstractFast charging/discharging rate, sustained cycle life, and high power density are irreplaceable virtues of supercapacitors (SCs), and these merits can be achieved by selecting suitable active materials and designing the rational microstructure. In this work, zinc cobalt sulfde (ZCS) microspheres have been synthesized by a simple two‐step method involving an ethylene glycol (EG) mediated solvothermal approach and subsequent sulfidation treatment. The formation mechanism of the microspheres is also proposed in detail by analyzing the time‐dependent SEM observations. Compared to ZCS nanosheets, ZCS microspheres achieve better electrochemical storage performance due to their satisfactory mesoporous feature, conductivity, and effective transport/diffusion paths for ions and electrons. When used as the electrode material of supercapacitor, ZCS microspheres not only obtain a large specific capacitance of 1516 F g−1 (211 mAh g−1) at 1 A g−1 with good rate capability of 1080 F g−1 (150 mAh g−1) at 10 A g−1, but also exhibit exceptional cycling stability with a capacitance reduced 6% of the initial specific capacitance at 10 A g−1 after 4000 cycles. An asymmetric supercapacitor using ZCS microspheres as the cathode and activated carbon (AC) as the anode is assembled, which achieves high specific capacitance (489.3 F g−1), energy density (152.9 Wh kg−1), and power density (750 W kg−1) at 1 A g−1 with the capacitance retention of 79% at 5 A g−1 after 2000 cycles. This work illustrates the promising application potential of the ZCS microspheres as the electrode material for electrochemical capacitors.
Efficient Antibacterial and Low Cytotoxic Potential of Silver Nanoparticles Produced Instantaneously Using Dimeric Gallate
Authors: Kumar Krishan , Saran Mukesh , Yadav Lalit , Shyamlal Bharti Rajesh Kumar , Mathur Manas , Bagaria Ashima , Chaudhary Sandeep 
Published: December 2018

AbstractThis study reports the instantaneous synthesis of stable silver nanoparticles (AgNPs) at room temperature using a digallate (DG) derivative linked through hydrophilic oxyethylene spacer. The DG derivative was synthesized using standard ester coupling reaction and employed for the production of AgNPs. The Digallate acted as a very strong reducing and stabilizing agent as it reduced Ag ions in an aqueous media into Ag nanoparticles (DG‐AgNPs) instantaneously at room temperature. The DG‐AgNPs were characterized by UV/Vis, XPS, XRD, HR‐TEM, SEM, AFM, DLS and zeta potential measurements and were evaluated for their antibacterial potential against four different strains (Escherichia coli, Staphylococcus aureus, Streptomyces griseus and Bacillus subtilis). It demonstrated strong inhibitory activity with minimum inhibitory concentrations (MIC) ranging from 4.0‐6.0 μg/ml against all the tested bacterial strains. Optical density (OD) measurements and live/dead cell staining assay revealed significant antibacterial action of DG‐AgNPs. The MTT based cytotoxicity, cellular morphology and nuclear staining analysis of NIH 3T3 cells (fibroblasts) suggested DG‐AgNPs to be relatively safe as it did not reveal any growth inhibition for the optimized antibacterial concentrations. Concisely, relatively non‐toxic AgNPs have been produced rapidly at room temperature using dimeric gallate and suggested as effective and promising antibacterial agent for pharmaceutical applications.
Novel SrCo0.9W0.1O3‐δ Hollow Fiber Ceramic Membrane with Enhanced Oxygen Delivery Performance and CO2 Resistance Ability
Authors: Yang Dong , Han Ning , Han Dezhi , Meng Bo , Wang Guangjian , Liu Shaomin 
Published: December 2018

AbstractThe development of the CO2‐resistant mixed ionic‐electronic conducting membranes can significantly expand their application into many CO2 involved processes, such as the oxy‐combustion process and green chemical synthesis in membrane reactors. In this work, the SrCo0.9W0.1O3‐δ (SCW) hollow fiber membranes were fabricated via a combined phase inversion and sintering method. The oxygen permeation flux of 4.18 mL min−1 cm−2 was achieved at 950 °C when pure He was used as sweep gas, while this flux can be further improved by 20.81% after Ag modification of outside membrane surface. Furthermore, the oxygen permeation behavior under CO2 in the sweep gas and surface morphology has been investigated. The oxygen permeation flux experienced a slight decline, then reached a plateau at 2.44 mL min−1 cm−2 during permeation evaluation of 70–100 hours at 900 °C when swept by 10% CO2‐containing gas mixture of 100 mL min−1. More interestingly, the oxygen permeation flux only exhibited 9.44% decrease of the original flux value after switching the sweeping gas back to He, which can be attributed to the formation of the porous layer on the inside surface of membrane. The porous layer would reduce the membrane thickness, meanwhile supply more inside membrane surface area, facilitating the oxygen permeation.
Binding Features of {M(3d)(cbdc)2} Blocks (M(3d)=VIVO, CuII; cbdc2–=Dianion of Cyclobutane‐1,1‐Dicarboxylic Acid) in Formation of Heterometallic Structures with d‐Metal Cations
Authors: Bazhina Evgeniya S. , Gogoleva Natalia V. , Aleksandrov Grigory G. , Kiskin Mikhail A. , Efimov Nikolay N. , Bogomyakov Artem S. , Ugolkova Elena A. , Minin Vadim V. , Sidorov Alexey A. , Eremenko Igor L. 
Published: December 2018

AbstractCompounds containing bis‐chelate dianionic blocks {M(3d)(cbdc)2}2– (M(3d)=VIVO, CuII) with cations VO2+ and Cu2+ chelated by two anions of dicarboxylic acid have been prepared as crystals when aqueous solutions of vanadyl sulfate VOSO4⋅3H2O or copper sulfate CuSO4⋅5H2O have been allowed to react with sulfates of d‐metals (MnII, CoII, NiII, ZnII, and CdII) and barium salt of cyclobutane‐1,1‐dicarboxylic acid (H2cbdc=C4H6(CO2H)2) in the 1:1:2 ratio. The nature of the M(3d) metal center has been found to influence on the structure of the heterometallic compounds formed. 1D polymers [M(VO)(cbdc)2(EtOH)2(H2O)3]n (M=Mn (1), Co (2), Ni (3)), molecular dinuclear complex [Zn(VO)(cbdc)2(H2O)5]⋅H2O (4), and 1D polymer {[Cd(VO)(cbdc)2(H2O)5]⋅H2O}n (5) are formed when M(3d)=VIVO, whereas in the case of the bis‐chelate block with the CuII atom, ionic compounds [M(H2O)6][Cu(cbdc)2(H2O)] (M=Mn (6), Co (7), Ni (8), Zn (9)) and 2D polymer {[CdCu(cbdc)2(H2O)2]⋅2H2O}n have been synthesized. The isolation of paramagnetic centers in compounds 1–10 is confirmed by magnetic measurements and EPR spectroscopy.
Regulating Lithium Nucleation via CNTs Modifying Carbon Cloth Film for Stable Li Metal Anode
Authors: Liu Fanfan , Xu Rui , Hu Zexun , Ye Shufen , Zeng Sifan , Yao Yu , Li Siqi , Yu Yan 
Published: December 2018

AbstractLi metal is demonstrated as one of the most promising anode materials for high energy density batteries. However, uncontrollable Li dendrite growth and repeated growth of solid electrolyte interface during the charge/discharge process lead to safety issues and capacity decay, preventing its practical application. To address these issues, an effective strategy is to realize uniform Li nucleation. Here, a stable lithium–scaffold composite electrode (CC/CNT@Li) is designed by melting of lithium metal into 3D interconnected lithiophilic carbon nanotube (CNT) on a porous carbon cloth (CC). The 3D interconnected CNTs successfully change the lithiophobic CC into lithiophilic nature, reducing the polarization of the electrode, ensuring homogenous Li nucleation and continuous smooth Li plating. The CNTs on the surface of CC provide adequate Li nucleation sites and reduce the areal current density to avoid Li dendrite growth. The 3D porous structure of CC/CNT offers enough free room for buffering the huge volume change during Li plating/stripping. The CC/CNT@Li composite anode exhibits dendrite‐free morphology and superior cycling performances over 500 h with low voltage hysteresis of 18, 23, and 71 mV at the current density of 1, 2, and 5 mA cm−2, respectively.
Resonant Energy Transfer can Trigger Multiexciton Recombination in Dense Quantum Dot Ensembles
Authors: Rafipoor Mona , Koll Rieke , Merkl Jan‐Philip , Fruhner Lisa Sarah , Weller Horst , Lange Holger 
Published: December 2018

AbstractCore/shell quantum dots/quantum rods are nanocrystals with typical application scenarios as ensembles. Resonance energy transfer is a possible process between adjacent nanocrystals. Highly excited nanocrystals can also relax energy by multiexciton recombination, competing against the energy transfer. The two processes have different dependencies and can be convolved, resulting in collective properties different from the superposition of the individual nanocrystals. A platform to study the interplay of energy transfer and multiexciton recombination is presented. CdSe/CdS quantum dot/quantum rods encapsulated in amphiphilic micelles with an interparticle distance control by spacer ligands are used for time‐resolved photoluminescence and transient absorption experiments. At exciton populations around one, the ensemble starts to be in a state where energy transfer can trigger multiexciton Auger recombination, altering the collective dynamics.
Metalloporphyrin Complex‐Based Nanosonosensitizers for Deep‐Tissue Tumor Theranostics by Noninvasive Sonodynamic Therapy
Authors: Ma Aiqing , Chen Huaqing , Cui Yanhong , Luo Zhenyu , Liang Ruijing , Wu Zhihao , Chen Ze , Yin Ting , Ni Jun , Zheng Mingbin , Cai Lintao 
Published: December 2018

AbstractMetal complexes are widely used as anticancer drugs, while the severe side effects of traditional chemotherapy require new therapeutic modalities. Sonodynamic therapy (SDT) provides a significantly noninvasive ultrasound (US) treatment approach by activating sonosensitizers and initiating reactive oxygen species (ROS) to damage malignant tissues. In this work, three metal 4‐methylphenylporphyrin (TTP) complexes (MnTTP, ZnTTP, and TiOTTP) are synthesized and encapsulated with human serum albumin (HSA) to form novel nanosonosensitizers. These nanosonosensitizers generate abundant singlet oxygen (1O2) under US irradiation, and importantly show excellent US‐activatable abilities with deep‐tissue depths up to 11 cm. Compared to ZnTTP‐HSA and TiOTTP‐HSA, MnTTP‐HSA exhibits the strongest ROS‐activatable behavior due to the lowest highest occupied molecular orbital−lowest unoccupied molecular orbital gap energy by density functional theory. It is also effective for deep‐tissue photoacoustic/magnetic resonance dual‐modal imaging to trace the accumulation of nanoparticles in tumors. Moreover, MnTTP‐HSA intriguingly achieves high SDT efficiency for simultaneously suppressing the growth of bilateral tumors away from ultrasound source in mice. This work develops a deep‐tissue imaging‐guided SDT strategy through well‐defined metalloporphyrin nanocomplexes and paves a new way for highly efficient noninvasive SDT treatments of malignant tumors.
Sub‐5 nm Metal Nanogaps: Physical Properties, Fabrication Methods, and Device Applications
Authors: Yang Yang , Gu Changzhi , Li Junjie 
Published: December 2018

AbstractSub‐5 nm metal nanogaps have attracted widespread attention in physics, chemistry, material sciences, and biology due to their physical properties, including great plasmon‐enhanced effects in light–matter interactions and charge tunneling, Coulomb blockade, and the Kondo effect under an electrical stimulus. These properties especially meet the needs of many cutting‐edge devices, such as sensing, optical, molecular, and electronic devices. However, fabricating sub‐5 nm nanogaps is still challenging at the present, and scaled and reliable fabrication, improved addressability, and multifunction integration are desired for further applications in commercial devices. The aim of this work is to provide a comprehensive overview of sub‐5 nm nanogaps and to present recent advancements in metal nanogaps, including their physical properties, fabrication methods, and device applications, with the ultimate aim to further inspire scientists and engineers in their research.
Optoregulated Drug Release from an Engineered Living Material: Self‐Replenishing Drug Depots for Long‐Term, Light‐Regulated Delivery
Authors: Sankaran Shrikrishnan , Becker Judith , Wittmann Christoph , del Campo Aránzazu 
Published: December 2018

AbstractOn‐demand and long‐term delivery of drugs are common requirements in many therapeutic applications, not easy to be solved with available smart polymers for drug encapsulation. This work presents a fundamentally different concept to address such scenarios using a self‐replenishing and optogenetically controlled living material. It consists of a hydrogel containing an active endotoxin‐free Escherichia coli strain. The bacteria are metabolically and optogenetically engineered to secrete the antimicrobial and antitumoral drug deoxyviolacein in a light‐regulated manner. The permeable hydrogel matrix sustains a viable and functional bacterial population and permits diffusion and delivery of the synthesized drug to the surrounding medium at quantities regulated by light dose. Using a focused light beam, the site for synthesis and delivery of the drug can be freely defined. The living material is shown to maintain considerable levels of drug production and release for at least 42 days. These results prove the potential and flexibility that living materials containing engineered bacteria can offer for advanced therapeutic applications.
The social media life of climate change: Platforms, publics, and future imaginaries
Authors: Pearce Warren , Niederer Sabine , Özkula Suay Melisa , Sánchez Querubín Natalia 
Published: December 2018

Social media is a transformative digital technology, collapsing the “six degrees of separation” which have previously characterized many social networks, and breaking down many of the barriers to individuals communicating with each other. Some commentators suggest that this is having profound effects across society, that social media have opened up new channels for public debates and have revolutionized the communication of prominent public issues such as climate change. In this article we provide the first systematic and critical review of the literature on social media and climate change. We highlight three key findings from the literature: a substantial bias toward Twitter studies, the prevalent approaches to researching climate change on social media (publics, themes, and professional communication), and important empirical findings (the use of mainstream information sources, discussions of “settled science,” polarization, and responses to temperature anomalies). Following this, we identify gaps in the existing literature that should be addressed by future research: namely, researchers should consider qualitative studies, visual communication and alternative social media platforms to Twitter. We conclude by arguing for further research that goes beyond a focus on science communication to a deeper examination of how publics imagine climate change and its future role in social life.This article is categorized under:
Perceptions, Behavior, and Communication of Climate Change > Communication
Simple identification of Al2O3 and MgO·Al2O3 spinel inclusions in steel using X‐ray‐excited optical luminescence
Authors: Imashuku Susumu , Wagatsuma Kazuaki 
Published: December 2018

Nonmetallic inclusions in steel cause problems in steel products and steel production. In particular, an analysis of Al2O3 and MgO·Al2O3 spinel inclusions is important since they are one of the most harmful inclusions. A rapid and simple analysis of nonmetallic inclusions is required as the conventional analytical methods for nonmetallic inclusions are time‐consuming. In this study, we propose a simple method to identify Al2O3 and MgO·Al2O3 spinel inclusions in steels. X‐ray‐excited optical luminescence (XEOL) analysis was selected as a promising method because it can rapidly identify sizes, shapes, and compositions of nonmetallic inclusions and can be performed in air. A model steel sample prepared by heating a mixture of Fe, Al, and MgO powders at 1550°C in argon atmosphere was used. XEOL images of the model steel sample showed that Al2O3 inclusions emitted blue and red luminescences. Using a filter attached to the camera, blocking light in the wavelength region above 650 nm, only the blue luminescence of the Al2O3 inclusions was observed. This was implemented as the luminescences of the Al2O3 inclusions appeared in both blue and red regions at wavelengths of 350, 485, 695, and 750 nm; consequently, the luminescences at 695 nm and 750 nm were blocked by the filter. In contrast, MgO·Al2O3 spinel inclusions emitted green luminescence (peak at 520 nm), unaffected by the filter. This indicates that we can simply identify Al2O3 and MgO·Al2O3 spinel inclusions by an XEOL image in the wavelength range of 420–650 nm.
Valence‐to‐core X‐ray emission spectroscopy of Ti, TiO, and TiO2 by means of a double full‐cylinder crystal von Hamos spectrometer
Authors: Wansleben Malte , Vinson John , Holfelder Ina , Kayser Yves , Beckhoff Burkhard 
Published: December 2018

We present valence‐to‐core X‐ray emission spectroscopy of Ti, TiO, and TiO2 by means of a double crystal von Hamos spectrometer based on full‐cylinder highly annealed pyrolytic graphite mosaic crystals. We demonstrate that, using a double crystal configuration, an energy resolution of E/ΔE ≈ 2,700 can be achieved in a compact setup using cylindrically curved optics with a radius of curvature of 50 mm. The stated energy resolution proved to be high enough to identify and determine chemical shifts of the Kβ2,5 and Kβ″ emission lines of both oxides. The experimental results are supported by calculations with the ab initio package OCEAN and compared with literature values.
Pharmaceutical Development of AAV-Based Gene Therapy Products for the Eye
Authors: Rodrigues Gerard A. , Shalaev Evgenyi , Karami Thomas K. , Cunningham James , Slater Nigel K. H. , Rivers Hongwen M. 
Published: December 2018

AbstractA resurgence of interest and investment in the field of gene therapy, driven in large part by advances in viral vector technology, has recently culminated in United States Food and Drug Administration approval of the first gene therapy product targeting a disease caused by mutations in a single gene. This product, LUXTURNA™ (voretigene neparvovec-rzyl; Spark Therapeutics, Inc., Philadelphia, PA), delivers a normal copy of the RPE65 gene to retinal cells for the treatment of biallelic RPE65 mutation–associated retinal dystrophy, a blinding disease. Many additional gene therapy programs targeting both inherited retinal diseases and other ocular diseases are in development, owing to an improved understanding of the genetic basis of ocular disease and the unique properties of the ocular compartment that make it amenable to local gene therapy. Here we review the growing body of literature that describes both the design and development of ocular gene therapy products, with a particular emphasis on target and vector selection, and chemistry, manufacturing, and controls.
Is Weak Supplementation analytic?
Authors: Cotnoir A. J. 
Published: December 2018

AbstractMereological principles are often controversial; perhaps the most stark contrast is between those who claim that Weak Supplementation is analytic—constitutive of our notion of proper parthood—and those who argue that the principle is simply false, and subject to many counterexamples. The aim of this paper is to diagnose the source of this dispute. I’ll suggest that the dispute has arisen by participants failing to be sensitive to two different conceptions of proper parthood: the outstripping conception and the non-identity conception. I’ll argue that the outstripping conception (together with a specific set of definitions for other mereological notions), can deliver the analyticity of Weak Supplementation on at least one sense of ‘analyticity’. I’ll also suggest that the non-identity conception cannot do so independently of considerations to do with mereological extensionality.