bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metal‐Free Decarboxylative Trichlorination of Alkynyl Carboxylic Acids: Synthesis of Trichloromethyl Ketones
Authors: Jayaraman Aravindan , Cho Eunjeong , Irudayanathan Francis Mariaraj , Kim Jimin , Lee Sunwoo 
Published: November 2017

Abstract2,2,2‐Trichloroacetophenone derivatives were synthesized via decarboxylative trichlorination from arylpropiolic acids and trichloroisocyanuric acid (TCCA). The reaction was performed in the presence of water at room temperature, and the desired products were obtained in good yields. The reaction showed good functional group tolerance towards halide, cyano, nitro, ketone, ester and aldehyde groups. In addition, the 2,2,2‐trichloroacetophenone derivatives were readily transformed into esters, amides, and hydrazides. Based on experiments with H218O (water‐18O), we proposed a cationic reaction pathway as the mechanism and suggested two different pathways for producing aryl‐ and alkyl‐substituted propiolic acids.magnified image
Site‐Specific Pre‐Swelling‐Directed Morphing Structures of Patterned Hydrogels
Authors: Wang Zhi Jian , Hong Wei , Wu Zi Liang , Zheng Qiang 
Published: November 2017

AbstractMorphing materials have promising applications in various fields, yet how to program the self‐shaping process for specific configurations remains a challenge. Herein we show a versatile approach to control the buckling of individual domains and thus the outcome configurations of planar‐patterned hydrogels. By photolithography, high‐swelling disc gels were positioned in a non‐swelling gel sheet; the swelling mismatch resulted in out‐of‐plain buckling of the disc gels. To locally control the buckling direction, masks with holes were used to guide site‐specific swelling of the high‐swelling gel under the holes, which built a transient through‐thickness gradient and thus directed the buckling during the subsequent unmasked swelling process. Therefore, various configurations of an identical patterned hydrogel can be programmed by the pre‐swelling step with different masks to encode the buckling directions of separate domains.
Modulating silica‐rubber interface by a biorenewable urushiol derivative. Synthesis, surface modification, and mechanical and dynamic mechanical properties of vulcanizates therefrom
Authors: Yan Xuesong , Hamed Gary R. , Jia Li 
Published: November 2017

ABSTRACTHydrogenated urushiol (i.e., 3‐pentadecylcatechol) can be used to directly modify silica particles via surface complexation with silicon. The degree of surface coverage can be varied by experimental conditions. Mooney viscosity and Payne effect studies of uncured rubber compounds show that dispersion of silica filler completely covered by hydrogenated urushiol in the absence of coupling agent bis[3‐(triethoxysilyl)propyl] tetrasulfide (TESPT) is as effective as dispersion of standard unmodified silica in the presence of TESPT under otherwise identical mixing conditions. Low bound rubber content and observation of filler flocculation at the early stage of vulcanization demonstrate that the filler‐rubber interaction is physical in nature as the result of surface modification by hydrogenated urushiol. When silica is partially covered by hydrogenated urushiol, it can be used in conjunction with TESPT. Judicial combination of partially covered silica and TESPT can give optimal properties to the resultant vulcanizate, including reduced Payne effect and improved cut resistance while maintaining other key parameters the same in comparison with a standard silica‐TESPT reinforced rubber. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45937.
Online prediction of the filtration performance of polypropylene melt blown nonwovens by blue‐colored glow
Authors: Zhang Haifeng , Liu Jinxin , Zhang Xing , Huang Chen , Jin Xiangyu 
Published: November 2017

ABSTRACTIn recently years, fine particulate matter (PM) pollution has drawn worldwide attention due to its serious threat to public health, visibility, climate, and ecosystems. The electret filter that can significantly improve the filtration efficiency without increasing the pressure drop has been widely used to for PM filtration. However, there were still some blind spots in the corona charging process, such as the interaction effects between the charging factors on the electret performances and the electric spark phenomenon during charging, which generate challenges for further improving the electret performance. Herein, we report an inconspicuous charging phenomenon that a blue‐colored glow was observed during corona charging process. We named it as “Waterfall glow”, because a lot of charges appear to flow. The relationship between the blue‐colored glow and the filtration efficiency was investigated. The results showed that the filtration performance of the electret melt blown was positively correlated to the intensity of blue‐colored glow. The phenomenon enables us to online predict the filtration performance of the electret material in the actual production. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45948.
Crystal and NMR Structures of a Peptidomimetic β‐Turn That Provides Facile Synthesis of 13‐Membered Cyclic Tetrapeptides
Authors: Cameron Alan J. , Squire Christopher J. , Edwards Patrick J. B. , Harjes Elena , Sarojini Vijayalekshmi 
Published: November 2017

AbstractHerein we report the unique conformations adopted by linear and cyclic tetrapeptides (CTPs) containing 2‐aminobenzoic acid (2‐Abz) in solution and as single crystals. The crystal structure of the linear tetrapeptide H2N‐d‐Leu‐d‐Phe‐2‐Abz‐d‐Ala‐COOH (1) reveals a novel planar peptidomimetic β‐turn stabilized by three hydrogen bonds and is in agreement with its NMR structure in solution. While CTPs are often synthetically inaccessible or cyclize in poor yield, both 1 and its N‐Me‐d‐Phe analogue (2) adopt pseudo‐cyclic frameworks enabling near quantitative conversion to the corresponding CTPs 3 and 4. The crystal structure of the N‐methylated peptide (4) is the first reported for a CTP containing 2‐Abz and reveals a distinctly planar 13‐membered ring, which is also evident in solution. The N‐methylation of d‐Phe results in a peptide bond inversion compared to the conformation of 3 in solution.
Racial disparity in utilization of therapeutic modalities among multiple myeloma patients: a SEER‐medicare analysis
Authors: Ailawadhi Sikander , Frank Ryan D. , Advani Pooja , Swaika Abhisek , Temkit M'hamed , Menghani Richa , Sharma Mayank , Meghji Zahara , Paulus Shumail , Khera Nandita , Hashmi Shahrukh K. , Paulus Aneel , Kakar Tanya S. , Hodge David O. , Colibaseanu Dorin T. , Vizzini Michael R. , Roy Vivek , Colon‐Otero Gerardo , Chanan‐Khan Asher A. 
Published: November 2017

AbstractOutcomes have improved considerably in multiple myeloma (MM), but disparities among racial‐ethnic groups exist. Differences in utilization of novel therapeutics are likely contributing factors. We explored such differences from the SEER‐Medicare database. A utilization analysis of lenalidomide, thalidomide, bortezomib, and stem cell transplant (SCT) was performed for patients diagnosed with MM between 2007 and 2009, including use over time, use by race, time‐dependent trends for each racial subgroup, and survival analysis. A total of 5338 MM patients were included with median 2.4‐year follow‐up. Within the first year of MM diagnosis, utilization of lenalidomide, bortezomib, SCT, and more than one novel agent increased over time while utilization of thalidomide decreased. There was significantly lower utilization of lenalidomide among African‐Americans (P < 0.01), higher thalidomide use among Hispanics and Asians (P < 0.01), and lower bortezomib use among Asians (P < 0.01). Hispanics had the highest median number of days to first dose of bortezomib (P = 0.02) and the lowest utilization of SCT (P < 0.01). Hispanics and Asians were the only groups without notable increases in lenalidomide and bortezomib use, respectively. SCT utilization increased over time for all except African‐Americans. SCT use within the first year after diagnosis was associated with better overall survival (HR 0.52; 95% CI: 0.4–0.68), while bortezomib use was associated with inferior survival (HR 1.14; 95% CI 1.02–1.28). We noted considerable variability in MM therapeutics utilization with seeming inequity for racial‐ethnic minorities. These trends should be considered to eliminate drug access and utilization disparities and achieve equitable benefit of therapeutic advances across all races.
Aerobic Oxygenation of Alkylarenes over Ultrafine Transition‐Metal‐Containing Manganese‐Based Oxides
Authors: Nakai Satoru , Uematsu Tsubasa , Ogasawara Yoshiyuki , Suzuki Kosuke , Yamaguchi Kazuya , Mizuno Noritaka 
Published: November 2017

AbstractThe oxygenation of alkylarenes to the corresponding aryl ketones is an important reaction, and the development of efficient heterogeneous catalysts that can utilize O2 as the sole oxidant is highly desired. In this study, we developed an efficient alkylarene oxygenation process catalyzed by ultrafine transition‐metal‐containing Mn‐based oxides with spinel or spinel‐like structures (M‐MnOx, M=Fe, Co, Ni, Cu). These M‐MnOx catalysts were prepared by a low‐temperature reduction method in 2‐propanol‐based solutions using tetra‐n‐butyl ammonium permanganate (TBAMnO4) as the Mn source, and they exhibited high Brunauer–Emmett–Teller surface areas (typically >400 m2 g−1). Using fluorene as the model substrate, the catalytic activities of M‐MnOx and Mn3O4 were compared. The catalytic activities of M‐MnOx were significantly higher than that of Mn3O4, which demonstrates that the incorporation of transition metals in manganese oxide was critical. Among the series of M‐MnOx catalysts examined, Ni‐MnOx exhibited the highest catalytic activity for the oxygenation. In addition, the catalytic activity of Ni‐MnOx was higher than that of a physical mixture of Mn3O4 and NiO. Furthermore, Ni‐MnOx exhibited a broad substrate scope with respect to various types of structurally diverse (hetero)alkylarenes (16 examples). The observed catalysis was truly heterogeneous, and the Ni‐MnOx catalyst was reusable for the oxygenation of fluorene at least three times and its high catalytic performance was preserved, for example, the reaction rate, final product yield, and product selectivity. The present Ni‐MnOx‐catalyzed oxygenation process is possibly initiated by a single‐electron oxidation process, and herein a plausible oxygen‐transfer mechanism is proposed based on several pieces of experimental evidence.
Porous Materials as Highly Efficient Electrocatalysts for the Oxygen Evolution Reaction
Authors: Qi Jing , Zhang Wei , Cao Rui 
Published: November 2017

AbstractCarbon‐neutral hydrogen has potential to alleviate the energy crisis and ease environmental problems. Water electrolysis is a sustainable way for large‐scale hydrogen production when electricity is generated from renewable energy resources. The key challenge in water splitting is the sluggish kinetics of the oxygen evolution reaction (OER). Thus, it is important and necessary to develop highly efficient electrocatalysts in a cost‐effective way for OER. Porous materials have proven to be versatile in catalysis due to their large surface area, the fast mass diffusion, and the buffer ability of volume change. Herein, we summarize the recent progress of representative methodologies for the synthesis of porous materials toward electrocatalytic OER. The materials discussed in this Review include the cheap transition‐metal‐based (Co, Ni, and Fe) and metal‐free porous materials. This Review sheds light on the different strategies to construct catalysts with porous structures to facilitate OER.
A PNNH Pincer Ligand Allows Access to Monovalent Iron
Authors: Polezhaev Alexander V. , Liss Cameron J. , Telser Joshua , Chen Chun‐Hsing , Caulton Kenneth G. 
Published: November 2017

AbstractReaction of the unsymmetrically armed pincer PNNH (phosphine‐pyridyl‐pyrazole) ligand with FeCl2 yielded the five‐coordinate monomer [(PNNH)FeCl2], the NH proton of which captures THF through the formation of a hydrogen bond. Deprotonation of this NH functionality with Li[N(SiMe3)2] did not give the four‐coordinate [(PNN)FeCl], but instead retained LiCl to yield [(PNNLi)FeCl2], in which the lithium bridges between the pyrazolate β‐nitrogen and one of the chlorides on iron. One‐electron reduction of this compound under CO occurred with the loss of LiCl to form the square‐pyramidal monovalent iron in [(PNN)Fe(CO)2], which was characterized by IR, Mössbauer, and EPR spectroscopy, X‐ray diffraction, and DFT calculations. Cyclic voltammetry studies of [(PNN)Fe(CO)2] showed a reversible reduction wave and the reduction product was synthesized by using KC8. The product K[(PNN)Fe(CO)2] contains saturated, five‐coordinate Fe0; the (PNN)Fe subunit is anionic and the K+ cations cluster close to the pyrazolate side of the two CO ligands. Potassium electrophile complete its coordination sphere through interactions with the oxygen atom of a CO of a neighboring unit, thereby creating a polymeric chain. The reaction of [(PNN)Fe(CO)2] with HBpin (4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolane) resulted in the reduction of the metal center (by release of H2) and borylation of the pyrazole β‐nitrogen atom. This redox‐active addition of the H−B bond across the metal–ligand assembly is an unusual example of metal–ligand cooperativity and establishes a ligand that supports iron in three different oxidation states.
Structural Tuning and Conformational Stability of Aromatic Oligoamide Foldamers
Authors: Annala Riia , Suhonen Aku , Laakkonen Heikki , Permi Perttu , Nissinen Maija 
Published: November 2017

AbstractA series of aromatic oligoamide foldamers with two or three pyridine‐2,6‐dicarboxamide units as their main folding motifs and varying aromatic building blocks as linkers have been synthetized to study the effects of the structural variation on the folding properties and conformational stability. Crystallographic studies showed that in the solid state the central linker unit either elongates the helices and more open S‐shaped conformations, compresses the helices to more compact conformations, or acts as a rigid spacer separating the pyridine‐2,6‐dicarboxamide units, which for their part add the predictability of the conformational properties. Multidimensional NMR studies showed that, even in solution, foldamers show conformational stability and folded conformations comparable to the solid‐state structures.
The First Alkaline‐Earth Fluorooxoborate Ba[B4O6F2]—Characterisation and Doping with Eu2+
Authors: Jantz Stephan G. , Pielnhofer Florian , van Wüllen Leo , Weihrich Richard , Schäfer Martin J. , Höppe Henning A. 
Published: November 2017

AbstractThe very first alkaline‐earth fluorooxoborate Ba[B4O6F2] was synthesised by solid state methods starting from Ba(BF4)2, β‐BaB2O4, and B2O3. The crystal structure derived from single‐crystal X‐ray diffraction (P21/n, a=6.6384(2) Å, b=7.6733(3) Å, c=11.3385(4) Å, β=91.281(2)°, Z=4, Rint=0.0269, R1=0.018, wR2=0.034) comprises layers of BO3F tetrahedra condensed through triangular BO3 units according to the descriptor 2Δ2□:<Δ2□>Δ. The extraordinary thirteen‐fold coordination of barium by oxygen and fluorine leads to interesting optical properties of a sample doped with divalent europium, where a 4f→4f emission was recorded around 359 nm together with a broad emission band of a 5d→4f emission peaking at 366 nm. The compound is further characterised by IR‐, Raman‐, and solid‐state NMR‐spectroscopic methods. Moreover, DFT calculations as well as TGA and DSC measurements were performed.
Au‐Coated Honeycomb Structure as an Efficient TCO‐Free Counter‐Electrode for Quantum‐Dot‐Sensitized Solar Cells
Authors: Dao Van‐Duong , Bui Van‐Tien , Baek Minki , Phan The‐Long , Yong Kijung , Choi Ho‐Suk 
Published: November 2017

AbstractThis study reports the fabrication of a Petri dish patterned with cylindrical micro‐cavities that are produced using a one‐step solvent‐immersion phase‐separation process. The developed 3D honeycomb Petri dish is coated with a Au film through a sputtering method to be an efficient Au‐coated FTO‐free electrode for quantum‐dot‐sensitized solar cells. Due to the high specific active surface area of the electrode with the Au‐coated honeycomb structure, the energy conversion efficiency of devices that use this electrode is 5.2 % compared to 4.4 and 4.7 % by devices using an Au‐coated flat Petri dish and an Au‐coated FTO electrode, respectively. This design strategy offers excellent potential for the fabrication of highly efficient counter electrodes with FTO‐free substrates of flexible photovoltaic devices.
Solar‐Driven Production of Hydrogen Peroxide from Water and Dioxygen
Authors: Fukuzumi Shunichi , Lee Yong‐Min , Nam Wonwoo 
Published: November 2017

AbstractHydrogen peroxide, which is a green oxidant and fuel, is produced by a two‐electron/two‐proton reduction of dioxygen, two‐electron/two‐proton oxidation of water, or a combination of four‐electron/four‐proton or/and two‐electron/two‐proton oxidation of water and two‐electron/two‐proton reduction of dioxygen. There are many reports on electrocatalysts for selective two‐electron/two‐proton reduction of dioxygen to produce hydrogen peroxide instead of four‐electron/four‐proton reduction of dioxygen to produce water. As compared with the two‐electron/two‐proton reduction of dioxygen to produce hydrogen peroxide, fewer catalysts are known for the selective two‐electron/two‐proton oxidation of water to produce hydrogen peroxide instead of four‐electron/four‐proton oxidation of water to evolve dioxygen. Thus, solar‐driven production of hydrogen peroxide mainly consists of the catalytic four‐electron/four‐proton oxidation of water and the catalytic two‐electron/two‐proton reduction of dioxygen. The overall reaction is the solar‐driven oxidation of water by dioxygen to produce hydrogen peroxide. Either or both the four‐electron/four‐proton or/and the two‐electron/two‐proton oxidation of water and the two‐electron/two‐proton reduction of dioxygen requires photocatalysts. The yield of hydrogen peroxide is improved when the compartment for the photocatalytic four‐electron/four‐proton or/and two‐electron/two‐proton oxidation of water is separated from that for the catalytic two‐electron/two‐proton reduction of dioxygen using a two‐compartment cell separated by a membrane. The overall solar‐driven oxidation of water by dioxygen, which is the greenest oxidant, to produce hydrogen peroxide can be combined with catalytic oxidation of various substrates by hydrogen peroxide
Photomodulation of DNA‐Templated Supramolecular Assemblies
Authors: Rubio‐Magnieto Jenifer , Phan Tuan‐Anh , Fossépré Mathieu , Matot Valérie , Knoops Jérémie , Jarrosson Thibaut , Dumy Pascal , Serein‐Spirau Françoise , Niebel Claude , Ulrich Sébastien , Surin Mathieu 
Published: November 2017

AbstractA new type of DNA ligand that contains a phosphate‐binding group and a photoresponsive azobenzene moiety is reported. When the azobenzene is in trans configuration, the ligand binds to the minor groove of a double‐stranded DNA, whereas it partially desorbs upon trans–cis isomerisation with light. The ability to photoswitch the ligand upon interaction with DNA is evidenced by (chir)optical signatures, and deciphered by the differences of binding geometry, stability, and dynamics of the DNA/ligand complexes for the two isomers. We exploit these properties to photomodulate DNA‐templated self‐assembly, through the incorporation of another π‐stacking DNA ligand, which together with the photoresponsive ligand form mixed supramolecular complexes along DNA. Our study demonstrates that well‐designed photoresponsive DNA binders can be used to modulate multicomponent supramolecular DNA assemblies.
Electronic and Structural Dynamics During the Switching of the Photomagnetic Complex [Fe(L222N5)(CN)2]
Authors: Zerdane Serhane , Collet Eric , Dong Xu , Matar Samir F. , Wang Hong Feng , Desplanches Cedric , Chastanet Guillaume , Chollet Matthieu , Glownia James M. , Lemke Henrick T. , Lorenc Maciej , Cammarata Marco 
Published: November 2017

AbstractThe [Fe(L222N5)(CN)2] compound, where L222N5 refers to the macrocyclic Schiff‐base ligand, 2,13‐dimethyl‐3,6,9,‐12,18‐pentaazabicyclo[12.3.1]octadeca‐1(18),2,12,14,‐ 16‐pentaene, is a photomagnetic FeII based coordination compound, which undergoes light‐induced excited spin‐state trapping (LIESST). The low spin state is hexacoordinated and the high spin state heptacoordinated. This system also serves as complex for the design of trinuclear or one‐dimensional compounds made of other types of bricks with diverse coordinated metals. Here its ultrafast spin‐state photoswitching dynamics are studied, by combining femtosecond optical spectroscopy and femtosecond X‐ray absorption measurements at the XPP station of the X‐ray free‐electron laser LCLS. DFT and TD‐DFT calculations are used to interpret experimental findings. These studies, performed in the solution phase, show that LIESST in [Fe(L222N5)(CN)2] occurs on the 100 fs timescale under different types of photoexcitation. In addition, coherent oscillations were observed, resulting from the structural dynamics accompanying LIESST, which were recently evidenced in more conventional octahedral FeIIN6 systems.
Tomographic Visualization of Single Droplets Inside Liquid‐Liquid Extraction Columns
Authors: Kögl Thilo , Arlt Wolfgang 
Published: November 2017

AbstractMithilfe der Röntgencomputertomographie kann die Fluiddynamik in verfahrenstechnischen Apparaten nicht‐invasiv untersucht werden. Durch die Wahl eines geeigneten Stoffsystems wird die disperse Tropfenströmung in Extraktionskolonnen tomographisch visualisiert. Die automatisierte Bildauswertung ermöglicht so zum ersten Mal den nicht‐invasiven Zugang zu Tropfengrößen, ‐formen und der örtlichen Verteilung der Tropfen im Inneren der strukturierten Metallpackungen. Entlang der Packungshöhe kann der Einfluss der strukturierten Packung auf die Tropfenverteilung detailliert untersucht werden.
Exploring the relationship between upgrading and capturing profits from GVC participation for disadvantaged suppliers in developing countries
Authors: Choksy Umair Shafi , Sinkovics Noemi , Sinkovics Rudolf R. 
Published: November 2017

AbstractThe existing literature on global value chains (GVCs) suggests that functional upgrading is a key determinant of whether suppliers are able to capture higher profits in GVCs. However, it is unclear whether the same argument holds for disadvantaged suppliers who face high barriers to achieving functional upgrading. Through a review of existing empirical studies, the present paper aims to explore how disadvantaged suppliers in developing countries increase their profits in the face of barriers to functional upgrading. The findings from the literature analysis suggest that the ability of disadvantaged suppliers to benefit from GVC participation depends on the extent of their managerial agency and their ability to leverage multiple upgrading/downgrading trajectories (whether product, process, or functional) and transform them into profitable outcomes. Copyright © 2017 ASAC. Published by John Wiley & Sons, Ltd.