bluuebunny/crossref_metadata_2025 huggingface dataset:
Closed‐flow column experiments: A numerical sensitivity analysis of reactive transport and parameter uncertainty
Authors: Ritschel Thomas , Totsche Kai Uwe
Published: July 2016

The identification of transport parameters by inverse modeling often suffers from equifinality or parameter correlation when models are fitted to measurements of the solute breakthrough in column outflow experiments. This parameter uncertainty can be approached by performing multiple experiments with different sets of boundary conditions, each provoking observations that are uniquely attributable to the respective transport processes. A promising approach to further increase the information potential of the experimental outcome is the closed‐flow column design. It is characterized by the recirculation of the column effluent into the solution supply vessel that feeds the inflow, which results in a damped sinusoidal oscillation in the breakthrough curve. In order to reveal the potential application of closed‐flow experiments, we present a comprehensive sensitivity analysis using common models for adsorption and degradation. We show that the sensitivity of inverse parameter determination with respect to the apparent dispersion can be controlled by the experimenter. For optimal settings, a decrease in parameter uncertainty as compared to classical experiments by an order of magnitude is achieved. In addition, we show a reduced equifinality between rate‐limited interactions and apparent dispersion. Furthermore, we illustrate the expected breakthrough curve for equilibrium and nonequilibrium adsorption, the latter showing strong similarities to the behavior found for completely mixed batch reactor experiments. Finally, breakthrough data from a reactive tracer experiment is evaluated using the proposed framework with excellent agreement of model and experimental results.
The impact of gravity waves and cloud nucleation threshold on stratospheric water and tropical tropospheric cloud fraction
Authors: Schoeberl Mark , Dessler Andrew , Ye Hao , Wang Tao , Avery Melody , Jensen Eric
Published: July 2016

Using the Modern Era Retrospective‐Analysis for Research and Applications (MERRA) and MERRA‐2 reanalysis winds, temperatures, and anvil cloud ice, we explore the impact of varying the cloud nucleation threshold relative humidity (RH) and high‐frequency gravity waves on stratospheric water vapor (H2O) and upper tropical tropopause cloud fraction (TCF). Our model results are compared to 2008/2009 winter TCF derived from Cloud‐Aerosol Lidar with Orthogonal Polarization and H2O observations from the Microwave Limb Sounder (MLS). The RH threshold affects both model H2O and TCF, while high‐frequency gravity waves mostly impact TCF. Adjusting the nucleation RH and the amplitude of high‐frequency gravity waves allows us to tune the model to observations. Reasonable observational agreement is obtained with a nucleation threshold between 130% and 150% RH consistent with airborne observations. For the MERRA reanalysis, we lower the tropopause temperature by 0.5 K roughly consistent with GPS radio occultation measurements and include ~0.1 K high‐frequency gravity wave temperature oscillations in order to match TCF and H2O observations. For MERRA‐2 we do not need to adjust the tropopause temperature nor add gravity waves, because there are sufficient high‐frequency temperature oscillations already present in the MERRA‐2 reanalysis to reproduce the observed TCF.
The profile of the rare earth elements in the Canada Basin, Arctic Ocean
Authors: Yang Jon , Haley Brian
Published: July 2016

We analyzed the dissolved rare earth element (REE) content of three water column profiles (two shelf sites and one deep basin site) in the Canada Basin in order to better constrain the behavior of REEs in the Arctic Ocean. Dissolved concentrations of the REEs in the surface are 1.3–1.9 times higher than deep water (>500 m) concentrations, which are constant with depth (La: 19–23 pM, Nd: 14–17 pM, Yb: 4.0–4.3 pM). The dominant source of REEs to the surface waters of the Canada Basin is most likely Pacific water flowing through the Bering Strait and Chukchi Sea and/or the Mackenzie River. Dissolved REEs in the intermediate and deep waters are constant and appear to behave conservatively, allowing us to investigate this aspect of REE behavior in the oceans. Calculated deep ocean residence times of the REEs in the Canada Basin range from 450 to 700 years and match the age of these waters. We postulate that these values are likely applicable to global deep ocean reservoirs and that observed deviations from this conservative value can help to constrain nonconservative processes acting on the REEs.
The interplay between assumed morphology and the direct radiative effect of light‐absorbing organic aerosol
Authors: Saleh Rawad , Adams Peter J. , Donahue Neil M. , Robinson Allen L.
Published: July 2016

Mie theory is widely employed in aerosol top‐of‐the‐atmosphere direct radiative effect (DRE) calculations and to retrieve the absorptivity of light‐absorbing organic aerosol (OA) from measurements. However, when OA is internally mixed with black carbon, it may exhibit complex morphologies whose optical behavior is imperfectly predicted by Mie theory, introducing bias in the retrieved absorptivities. We performed numerical experiments and global radiative transfer modeling (RTM) to investigate the effect of this bias on the calculated absorption and thus the DRE. We show that using true OA absorptivity, retrieved with a realistic representation of the complex morphology, leads to significant errors in DRE when the RTM employs the simplified Mie theory. On the other hand, when Mie theory is consistently applied in both OA absorptivity retrieval and the RTM, the errors largely cancel out, yielding accurate DRE. As long as global RTMs use Mie theory, they should implement parametrizations of light‐absorbing OA derived from retrievals based on Mie theory.
InSAR observations of strain accumulation and fault creep along the Chaman Fault system, Pakistan and Afghanistan
Authors: Fattahi Heresh , Amelung Falk
Published: July 2016

We use 2004–2011 Envisat synthetic aperture radar imagery and InSAR time series methods to estimate the contemporary rates of strain accumulation in the Chaman Fault system in Pakistan and Afghanistan. At 29 N we find long‐term slip rates of 16 ± 2.3 mm/yr for the Ghazaband Fault and of 8 ± 3.1 mm/yr for the Chaman Fault. This makes the Ghazaband Fault one of the most hazardous faults of the plate boundary zone. We further identify a 340 km long segment displaying aseismic surface creep along the Chaman Fault, with maximum surface creep rate of 8.1 ± 2 mm/yr. The observation that the Chaman Fault accommodates only 30% of the relative plate motion between India and Eurasia implies that the remainder is accommodated south and east of the Katawaz block microplate.
A 2‐D tomographic model of the Juan de Fuca plate from accretion at axial seamount to subduction at the Cascadia margin from an active source ocean bottom seismometer survey
Authors: Horning G. , Canales J. P. , Carbotte S. M. , Han S. , Carton H. , Nedimović M. R. , van Keken P. E.
Published: July 2016

We report results from a wide‐angle controlled source seismic experiment across the Juan de Fuca plate designed to investigate the evolution of the plate from accretion at the Juan de Fuca ridge to subduction at the Cascadia margin. A two‐dimensional velocity model of the crust and upper mantle is derived from a joint reflection‐refraction traveltime inversion. To interpret our tomography results, we first generate a plausible baseline velocity model, assuming a plate cooling model and realistic oceanic lithologies. We then use an effective medium theory to infer from our tomography results the extent of porosity, alteration, and water content that would be required to explain the departure from the baseline model. In crust of ages >1 Ma and away from propagator wakes and regions of faulting due to plate bending, we obtain estimates of upper crustal hydration of 0.5–2.1 wt % and find mostly dry lower crust and upper mantle. In sections of the crust affected by propagator wakes we find upper estimates of upper crustal, lower crustal, and upper mantle hydration of 3.1, 0.8, and 1.8 wt %, respectively. At the Cascadia deformation front, we find that the amount of water stored at uppermost mantle levels in the downgoing JdF plate is very limited (<0.3 wt %), with most of the water carried into the subduction zone being stored in the oceanic crust.
Identification of temporal consistency in rating curve data: Bidirectional Reach (BReach)
Authors: Van Eerdenbrugh Katrien , Van Hoey Stijn , Verhoest Niko E. C.
Published: July 2016

In this paper, a methodology is developed to identify consistency of rating curve data based on a quality analysis of model results. This methodology, called Bidirectional Reach (BReach), evaluates results of a rating curve model with randomly sampled parameter sets in each observation. The combination of a parameter set and an observation is classified as nonacceptable if the deviation between the accompanying model result and the measurement exceeds observational uncertainty. Based on this classification, conditions for satisfactory behavior of a model in a sequence of observations are defined. Subsequently, a parameter set is evaluated in a data point by assessing the span for which it behaves satisfactory in the direction of the previous (or following) chronologically sorted observations. This is repeated for all sampled parameter sets and results are aggregated by indicating the endpoint of the largest span, called the maximum left (right) reach. This temporal reach should not be confused with a spatial reach (indicating a part of a river). The same procedure is followed for each data point and for different definitions of satisfactory behavior. Results of this analysis enable the detection of changes in data consistency. The methodology is validated with observed data and various synthetic stage‐discharge data sets and proves to be a robust technique to investigate temporal consistency of rating curve data. It provides satisfying results despite of low data availability, errors in the estimated observational uncertainty, and a rating curve model that is known to cover only a limited part of the observations.
On Local Phase Equilibria and the Appearance of Nanoparticles in the Microstructure of Single‐Crystal Ni‐Base Superalloys
Authors: Yardley Victoria , Povstugar Ivan , Choi Pyuck‐Pa , Raabe Dirk , Parsa Alireza B. , Kostka Aleksander , Somsen Christoph , Dlouhy Antonin , Neuking Klaus , George Easo P. , Eggeler Gunther
Published: July 2016

High‐resolution characterization techniques are combined with thermodynamic calculations (CALPHAD) to rationalize microstructural features of single crystal Ni‐base superalloys. Considering the chemical compositions of dendritic and interdendritic regions one can explain differences in γ′‐volume fractions. Using thermodynamic calculations one can explain, why γ‐nanoparticles are observed in the central regions of large cuboidal γ′‐particles and why tertiary γ′‐nanoparticles form in the γ‐channels. The chemical compositions of the γ‐channels and of the newly formed γ‐particles differ because of the Gibbs–Thomson pressure which acts on the small particles. With increasing size of secondary γ′‐particles, their shape changes from spherical to cuboidal. Some general thermodynamic aspects including the temperature dependencies of the Gibbs free energy G, the enthalpy H, and the entropy S and site occupancies in the ordered L12 (γ′) phase are considered. The importance of cooling rate after homogenization is discussed.
Microstructures and Mechanical Properties of Commercial Hot‐Extruded Copper Processed by Torsion Deformation
Authors: Guo Ning , Li Xiaoxia , Xiao Mei , Xin Renlong , Chai Linjiang , Song Bo , Yu Hongbing , Li Lu
Published: July 2016

Free‐end torsion deformation is used for processing copper rod in this work. Both microstructures and mechanical properties of the torsional rods are quantitatively analyzed. The results show that gradient lamellar dislocation substructures (LDS) along the radial direction as the main defects are formed after torsion. The increment of the LDS density, the shrinking of spacing size, and the change of length/spacing (L/S) ratio of the LDS are all non‐monotonic function of torsion revolution. High‐density LDS with fine spacing can retain strain hardening capability, which results in good combination of high tensile strength and good ductility in the torsional deformed sample with large number of revolutions. The influence of torsion strain on primary twin boundaries (TBs) in the hot‐extruded rod is also discussed.
Synthesis of Self‐Assembled Spermidine‐Carbon Quantum Dots Effective against Multidrug‐Resistant Bacteria
Authors: Li Yu‐Jia , Harroun Scott G. , Su Yu‐Chia , Huang Chun‐Fang , Unnikrishnan Binesh , Lin Han‐Jia , Lin Chia‐Hua , Huang Chih‐Ching
Published: July 2016

This study reports a two‐step method to synthesize spermidine‐capped fluorescent carbon quantum dots (Spd–CQDs) and their potential application as an antibacterial agent. Fluorescent carbon quantum dots (CQDs) are synthesized by pyrolysis of ammonium citrate in the solid state and then modified with spermidine by a simple heating treatment without a coupling agent. Spermidine, a naturally occurring polyamine, binds with DNA, lipids, and proteins involved in many important processes within organisms such as DNA stability, and cell growth, proliferation, and death. The antimicrobial activity of the as‐synthesized Spd–CQDs (size ≈4.6 nm) has been tested against non‐multidrug‐resistant E. coli, S. aureus, B. subtilis, and P. aeruginosa bacteria and also multidrug‐resistant bacteria, methicillin‐resistant S. aureus (MRSA). The minimal inhibitory concentration value of Spd–CQDs is much lower (>25 000‐fold) than that of spermidine, indicating their promising antibacterial characteristics. The mechanism of antibacterial activity is investigated, and the results indicate that Spd–CQDs cause significant damage to the bacterial membrane. In vitro cytotoxicity and hemolysis analyses reveal the high biocompatibility of Spd–CQDs. To demonstrate its practical application, in vitro MRSA‐infected wound healing studies in rats have been conducted, which show faster healing, better epithelialization, and formation of collagen fibers when Spd–CQDs are used as a dressing material.
Silver‐Mediated Phosphonylation of C(sp2)−H Bonds with P−H Bonds: Direct C−H Functionalization of Ferrocenyl Anilides and Dialkyl Phosphites under Palladium‐ and Copper‐Free Conditions
Authors: Yu Xiaoli , Ge Bingyang , Zhang Yaxuan , Wang Xiaoli , Wang Dawei
Published: July 2016

A direct, silver‐mediated C−H phosphonylation reaction of ferrocenyl anilides and dialkyl phosphites was developed. This methodology can tolerate a variety of functional groups and is free of palladium and copper. Moreover, mechanistic studies have revealed that the reaction pathway is of a radical type.
The Interplay Between Conformation and Absolute Configuration in Chiral Electron Dynamics of Small Diols
Authors: Daly Steven , Tia Maurice , Garcia Gustavo A. , Nahon Laurent , Powis Ivan
Published: July 2016

A competition between chiral characteristics alternatively attributable to either conformation or to absolute configuration is identified. Circular dichroism associated with photoexcitation of the outer orbital of configurational enantiomers of 1,3‐ and 2,3‐butanediols has been examined with a focus on the large changes in electron chiral asymmetry produced by different molecular conformations. Experimental gas‐phase measurements offer support for the theoretical modeling of this chiroptical effect. A surprising prediction is that a conformationally produced pseudo‐enantiomerism in 1,3‐butanediol generates a chiral response in the frontier electron dynamics that outweighs the influence of the permanent configurational handedness established at the asymmetrically substituted carbon. Induced conformation, and specifically induced conformational chirality, may thus be a dominating factor in chiral molecular recognition in such systems.
The Enantioselective Total Synthesis of Exochomine
Authors: Gao Alison X. , Hamada Tomoaki , Snyder Scott A.
Published: July 2016

Molecules that possess fully substituted chiral centers are often challenging to construct, particularly if those centers connect two seemingly different halves or include a nitrogen atom. Herein, we describe an efficient approach to a molecule that combines both challenges in a single center in the form of exochomine. Failures in direct coupling led to a design fueled by highly specific reaction conditions for several steps and the development of an improved protocol for 1,4‐reduction in a hindered context where numerous side reactions were possible. These chemoselective solutions should have value to other problems. Challenges in obtaining matching spectral data for the synthesized natural product are also discussed.
Controlled Gas Exfoliation of Boron Nitride into Few‐Layered Nanosheets
Authors: Zhu Wenshuai , Gao Xiang , Li Qian , Li Hongping , Chao Yanhong , Li Meijun , Mahurin Shannon M. , Li Huaming , Zhu Huiyuan , Dai Sheng
Published: July 2016

The controlled exfoliation of hexagonal boron nitride (h‐BN) into single‐ or few‐layered nanosheets remains a grand challenge and becomes the bottleneck to essential studies and applications of h‐BN. Here, we present an efficient strategy for the scalable synthesis of few‐layered h‐BN nanosheets (BNNS) using a novel gas exfoliation of bulk h‐BN in liquid N2 (L‐N2). The essence of this strategy lies in the combination of a high temperature triggered expansion of bulk h‐BN and the cryogenic L‐N2 gasification to exfoliate the h‐BN. The produced BNNS after ten cycles (BNNS‐10) consisted primarily of fewer than five atomic layers with a high mass yield of 16–20 %. N2 sorption and desorption isotherms show that the BNNS‐10 exhibited a much higher specific surface area of 278 m2 g−1 than that of bulk BN (10 m2 g−1). Through the investigation of the exfoliated intermediates combined with a theoretical calculation, we found that the huge temperature variation initiates the expansion and curling of the bulk h‐BN. Subseqently, the L‐N2 penetrates into the interlayers of h‐BN along the curling edge, followed by an immediate drastic gasification of L‐N2, further peeling off h‐BN. This novel gas exfoliation of high surface area BNNS not only opens up potential opportunities for wide applications, but also can be extended to produce other layered materials in high yields.
Thin Heterojunctions and Spatially Separated Cocatalysts To Simultaneously Reduce Bulk and Surface Recombination in Photocatalysts
Authors: Li Ang , Chang Xiaoxia , Huang Zhiqi , Li Chengcheng , Wei Yijia , Zhang Lei , Wang Tuo , Gong Jinlong
Published: July 2016

Efficient charge separation and light absorption are crucial for solar energy conversion over solid photocatalysts. This paper describes the construction of Pt@TiO2@In2O3@MnOx mesoporous hollow spheres (PTIM‐MSs) for highly efficient photocatalytic oxidation. TiO2–In2O3 double‐layered shells were selectively decorated with Pt nanoparticles and MnOx on the inner and outer surfaces, respectively. The spatially separated cocatalysts drive electrons and holes near the surface to flow in opposite directions, while the thin heterogeneous shell separates the charges generated in the bulk phase. The synergy between the thin heterojunctions and the spatially separated cocatalysts can simultaneously reduce bulk and surface/subsurface recombination. In2O3 also serves as a sensitizer to enhance light absorption. The PTIM‐MSs exhibit high photocatalytic activity for both water and alcohol oxidation.
Single‐Molecule Sensors: Challenges and Opportunities for Quantitative Analysis
Authors: Gooding J. Justin , Gaus Katharina
Published: July 2016

Measurement science has been converging to smaller and smaller samples, such that it is now possible to detect single molecules. This Review focuses on the next generation of analytical tools that combine single‐molecule detection with the ability to measure many single molecules simultaneously and/or process larger and more complex samples. Such single‐molecule sensors constitute a new type of quantitative analytical tool, as they perform analysis by molecular counting and thus potentially capture the heterogeneity of the sample. This Review outlines the advantages and potential of these new, quantitative single‐molecule sensors, the measurement challenges in making single‐molecule devices suitable for analysis, the inspiration biology provides for overcoming these challenges, and some of the solutions currently being explored.
Hydrogels from Amorphous Calcium Carbonate and Polyacrylic Acid: Bio‐Inspired Materials for “Mineral Plastics”
Authors: Sun Shengtong , Mao Li‐Bo , Lei Zhouyue , Yu Shu‐Hong , Cölfen Helmut
Published: July 2016

Given increasing environmental issues due to the large usage of non‐biodegradable plastics based on petroleum, new plastic materials, which are economic, environmentally friendly, and recyclable are in high demand. One feasible strategy is the bio‐inspired synthesis of mineral‐based hybrid materials. Herein we report a facile route for an amorphous CaCO3 (ACC)‐based hydrogel consisting of very small ACC nanoparticles physically cross‐linked by poly(acrylic acid). The hydrogel is shapeable, stretchable, and self‐healable. Upon drying, the hydrogel forms free‐standing, rigid, and transparent objects with remarkable mechanical performance. By swelling in water, the material can completely recover the initial hydrogel state. As a matrix, thermochromism can also be easily introduced. The present hybrid hydrogel may represent a new class of plastic materials, the “mineral plastics”.
Highly Tunable Selectivity for Syngas‐Derived Alkenes over Zinc and Sodium‐Modulated Fe5C2 Catalyst
Authors: Zhai Peng , Xu Cong , Gao Rui , Liu Xi , Li Mengzhu , Li Weizhen , Fu Xinpu , Jia Chunjiang , Xie Jinglin , Zhao Ming , Wang Xiaoping , Li Yong‐Wang , Zhang Qianwen , Wen Xiao‐Dong , Ma Ding
Published: July 2016

Zn‐ and Na‐modulated Fe catalysts were fabricated by a simple coprecipitation/washing method. Zn greatly changed the size of iron species, serving as the structural promoter, while the existence of Na on the surface of the Fe catalyst alters the electronic structure, making the catalyst very active for CO activation. Most importantly, the electronic structure of the catalyst surface suppresses the hydrogenation of double bonds and promotes desorption of products, which renders the catalyst unexpectedly reactive toward alkenes—especially C5+ alkenes (with more than 50% selectivity in hydrocarbons)—while lowering the selectivity for undesired products. This study enriches C1 chemistry and the design of highly selective new catalysts for high‐value chemicals.
Highly Efficient Synthesis of Multiantennary Bisected N‐glycans Based on Imidates
Authors: Mönnich Manuel , Eller Steffen , Karagiannis Theodoros , Perkams Lukas , Luber Thomas , Ott Dimitri , Niemietz Mathäus , Hoffman Joanna , Walcher Janika , Berger Lukas , Pischl Matthias , Weishaupt Markus , Wirkner Cathrin , Lichtenstein Rachel G. , Unverzagt Carlo
Published: July 2016

The occurrence of N‐glycans with a bisecting GlcNAc modification on glycoproteins has many implications in developmental and immune biology. However, these particular N‐glycans are difficult to obtain either from nature or through synthesis. We have developed a flexible and general method for synthesizing bisected N‐glycans of the complex type by employing modular TFAc‐protected donors for all antennae. The TFAc‐protected N‐glycans are suitable for the late introduction of a bisecting GlcNAc. This integrated strategy permits for the first time the use of a single approach for multiantennary N‐glycans as well as their bisected derivatives via imidates, with unprecedented yields even in a one‐pot double glycosylation. With this new method, rare N‐glycans of the bisected type can be obtained readily, thereby providing defined tools to decipher the biological roles of bisecting GlcNAc modifications.
Carbonylation of Difluoroalkyl Bromides Catalyzed by Palladium
Authors: Zhao Hai‐Yang , Feng Zhang , Luo Zhiji , Zhang Xingang
Published: July 2016

Although important progress has been made in the fluoroalkylation reactions, the transition‐metal‐catalyzed carbonylative fluoroalkylation reaction remains challenging so far. Herein, we report the first example of a Pd‐catalyzed carbonylation of difluoroalkyl bromides with (hetero)arylboronic acids under one atmosphere pressure of CO. The reaction can also be extended to the aryl potassium trifluoroborate salts. The advantages of this protocol are synthetic simplicity, broad substrate scope, and excellent functional group compatibility. The resulting difluoroalkyl ketones can serve as versatile building blocks for the synthesis of various useful fluorinated compounds.
Supported ionic liquids as green catalyst for 2‐butanol synthesis from transesterification of sec‐butyl acetate
Authors: Yang Jinbei , Zeng Ting , Cai Dongren , Li Ling , Tang Wenli , Hong Ruoyu , Qiu Ting
Published: July 2016

Two supported ionic liquids using molecular sieve SBA‐15 as supporter were prepared and employed as efficient catalysts for the synthesis of 2‐butanol (SBOH) via the transesterification of sec‐butyl acetate and methanol (MeOH). [SBA‐15‐Ps‐im]HSO4 performed better in the catalytic activity and was chosen for further studying the influence of experimental conditions. The effects of various parameters, such as the catalyst dosage, initial reactant molar ratio, and reaction time on the reaction were investigated systematically. The maximum conversion of sec‐butyl acetate (89.2%) was obtained under the optimum reaction conditions. In addition, the catalyst of supported ionic liquids can be easily separated by simple filtration, and the reusability test indicates that the catalyst has outstanding utility for repeated use. © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.
Characterization and properties of LDPE film with gallic‐acid‐based oxygen scavenging system useful as a functional packaging material
Authors: Ahn Byung Joon , Gaikwad Kirtiraj K. , Lee Youn Suk
Published: July 2016

We prepared and characterized active, oxygen‐scavenging, low density polyethylene (LDPE) films from a non‐metallic‐based oxygen scavenging system (OSS) containing 1, 3, 5, 10, and 20% of gallic acid (GA) and potassium chloride (PC). We compared the surface morphology and mechanical, permeability, and optical properties of the oxygen‐scavenging LDPE film with those of pure LDPE film. The surface morphology, gas barrier, and thermal properties indicate that the OSS was well incorporated into the LDPE film structure. The surface roughness of the film increased with the amount of oxygen scavenging material. The oxygen and water vapor permeability of the developed film also increased with the amount of oxygen scavenging material, though its elongation decreased. The oxygen scavenging capability of the prepared film was analyzed at different temperatures. The initial oxygen content (%) in the vial headspace, 20.90%, decreased to 16.6% at 4 °C, 14.6% at 23 °C, and 12.7% at 50 °C after 7 days of storage with the film containing 20% OSS. The film impregnated with 20% organic oxygen scavenging material showed an effective oxygen scavenging capacity of 0.709 mL/cm2 at 23 °C. Relative humidity triggered the oxygen scavenging reaction. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44138.
Spray‐dried microparticles composed of cinnamoyl poly(N‐isopropylacrylamide‐co‐hydroxyethylacrylate) and gold nanoparticle
Authors: Zhang Hong , Kim Jin‐Chul
Published: July 2016

Temperature‐ and NIR irradiation‐responsive microparticles composed of cinnamoyl poly(N‐isopropylacrylamide‐co‐hydroxyethylacrylate) [CinP(NIPAM‐HEA)] and gold nanoparticle (GNP) were prepared by a spray‐drying method. According to the cloud points determined by an optical method, the HEA content in P(NIPAM‐HEA) had no marked effect on the lower critical solution temperature (LCST). However, the cinnamoyl group content in CinP(NIPAM‐HEA) had a significant effect on the LCST. The LCSTs determined by a calorimetric method was in agreement with those determined by an optical method. The hydrodynamic mean diameter of gold nanoparticle (GNP) prepared by reducing gold ions was about 30 nm and it seemed to be a nanosphere on TEM photo. Spray‐dried CinP(NIPAM‐HEA) microparticles containing GNP was 1.5 μm to 12 μm in diameter on SEM photo. Gold was detected on the energy‐dispersive X‐ray spectrum of the microparticles. The amount of FITC‐dextran released for 12 h from the microparticles was much higher at temperatures above the LCST (at 37 °C and 45 °C) than below the LCST (at 20 °C and 25 °C). The cumulative release amount in 12 h was only about 3% without NIR irradiation, whereas the value was about 26.5% when NIR was irradiated to the microparticle suspension. The photothermal energy generated by GNP was believed to render the thermosensitive copolymers de‐swollen and hydrophobic, allowing for the active release of dye from the microparticles. The NIR irradiation‐responsive GNP‐loaded microparticles could be applied to the development of NIR‐responsive drug carriers which release their contents in response to an external stimulus (i.e., NIR irradiation). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44141.
Helical Polyacetylene‐Based Switchable Chiral Columnar Phases: Frustrated Chain Packing and Two‐Way Shape Actuator
Authors: Wang Jun , Liu Xiao‐Qing , Ren Xiang‐Kui , Zhang Ben , Yang Shuang , Cao Yu , Liu Feng , Lotz Bernard , Chen Er‐Qiang
Published: July 2016

Chiral columns formed by a helical cis‐polyphenylacetylene (PPA) derivative P1 are reversibly switched during a phase transition between two chiral columnar phases: the frustrated Φh3D‐SL phase containing four chains at low temperature and a hexagonal columnar phase Φh at high temperature, accompanied by a simultaneous conformational change. The helix–helix transition along the PPA backbone during the Φh3D‐SL‐Φh transition makes the uniaxially oriented P1 capable of reversibly and reproducibly elongating (132 %) upon heating and contracting upon cooling, exhibiting the behavior of a two‐way shape actuator.
Constraining the Milky Way assembly history with Galactic Archaeology
Authors: Minchev I.
Published: July 2016

The aim of Galactic Archaeology is to recover the evolutionary history of the Milky Way from its present day kinematical and chemical state. Because stars move away from their birth sites, the current dynamical information alone is not sufficient for this task. The chemical composition of stellar atmospheres, on the other hand, is largely preserved over the stellar lifetime and, together with accurate ages, can be used to recover the birthplaces of stars currently found at the same Galactic radius. In addition to the availability of large stellar samples with accurate 6D kinematics and chemical abundance measurements, this requires detailed modeling with both dynamical and chemical evolution taken into account. An important first step is to understand the variety of dynamical processes that can take place in the Milky Way, including the perturbative effects of both internal (bar and spiral structure) and external (infalling satellites) agents. We discuss here (1) how to constrain the Galactic bar, spiral structure, and merging satellites by their effect on the local and global disc phase‐space, (2) the effect of multiple patterns on the disc dynamics, and (3) the importance of radial migration and merger perturbations for the formation of the Galactic thick disc. Finally, we discuss the construction of Milky Way chemo‐dynamical models and relate to observations. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Continuous precipitation of process related impurities from clarified cell culture supernatant using a novel coiled flow inversion reactor (CFIR)
Authors: Kateja Nikhil , Agarwal Harshit , Saraswat Aditya , Bhat Manish , Rathore Anurag S.
Published: July 2016

Coiled Flow Inverter Reactor (CFIR) has recently been explored for facilitating continuous operation of several unit operations involved in downstream processing of biopharmaceuticals such as viral inactivation and protein refolding. The application of CFIR for continuous precipitation of clarified cell culture supernatant has been explored. The pH based precipitation is optimized in the batch mode and then in the continuous mode in CFIR using a design of experiments (DOE) study. Improved clearance of host cell DNA (52× vs. 39× in batch), improved clearance of host cell proteins (HCP) (7× vs. 6× in batch) and comparable recovery (90 vs. 91.5 % in batch) are observed along with six times higher productivity. To further demonstrate wider applicability of CFIR in performing continuous precipitation, two more case studies involving use of two different precipitation protocols (CaCl2 based and caprylic acid based) are also performed. In both cases, clearance of host cell DNA, HCP, and product recovery are found to be comparable or better in CFIR than in batch operations. Moreover, increase in productivity of 16 times (CaCl2 based) and eight times (caprylic acid based) is obtained for the two precipitation protocols, respectively. The data clearly demonstrate that CFIR can be seamlessly integrated into a continuous bioprocess train for performing continuous precipitation of clarified cell culture supernatant. To our knowledge this is the first report of such use.
Diversity Oriented Synthesis of Natural 2‐Arylbenzofuran, Moracin F
Authors: Yun So‐Ra , Jun Jong‐Gab
Published: July 2016

Diversity oriented synthesis of natural 2‐arylbenzofuran, moracin F (1) has been carried out from the commercially available starting materials using Sonogashira coupling, Suzuki coupling, neutral Al2O3
mediated cyclization, and intramolecular Wittig reaction as key steps.
Fast and Simple Chemical Fingerprinting Analysis of Medicinal Herbs by Paper Cone Spray Ionization Mass Spectrometry (PCSI MS)
Authors: Jun Gyuwoong , Park Tae‐Min , Cha Sangwon
Published: July 2016

Paper cone spray ionization (PCSI), an extractive ambient ionization method that is specialized for raw solid material analysis, was applied to chemical fingerprinting analysis of raw medicinal herbs. Experimental parameters of PCSI mass spectrometry (MS) were first optimized against Salvia miltiorrhiza Bunge (danshen). Our results showed that simple alkyl alcohols, such as methanol and 2‐propanol, generally worked well in both polarities and could generate representative chemical fingerprints instantly for a given herbal sample. In addition, in situ extraction from untreated herbal slices during PCSI MS was found to be enough to generate characteristic chemical signatures of a given medicinal herb. After optimization, representative fingerprints of various medicinal herbs, including Sophora flavescens (kushen) and Paeonia lactiflora Pall (shaoyao), were successfully obtained by PCSI MS. In addition, morphologically similar herbs, Cynanchum auriculatum and Cynanchum wilfordii, could be differentiated from each other by their chemical signatures by PCSI MS.
Identification and Synthesis of Branched Wax‐type Esters, Novel Surface Lipids from the Spider Argyrodes elevatus (Araneae: Theridiidae)
Authors: Chinta Satya Prabhakar , Goller Stephan , Uhl Gabriele , Schulz Stefan
Published: July 2016

The analysis of cuticular extracts from the kleptoparasitic spider Argyrodes elevatus revealed the presence of unusual esters, new for arthropods. These novel compounds proved to be methyl‐branched long‐chain fatty acid esters with methyl branches located either close or remote from the internally located ester group. The GC/MS analysis of the prosoma lipid blend from the male cuticle contained one major component, undecyl 2‐methyltridecanoate (1). In contrast, four major wax‐type esters, 2‐methylundecyl 2,8‐dimethylundecanoate (2), 2,8‐dimethylundecyl 2,8‐dimethylundecanoate (3), heptadecyl 4‐methylheptanoate (4), and 14‐methylheptadecyl 4‐methylheptanoate (5), were identified in the lipid blend of female prosomata. Structure assignments were based on mass spectra, gas chromatographic retention indices, and microderivatization. Unambiguous proof of postulated structures was ensured by an independent synthesis of all five esters. Preferentially, odd‐numbered carbon chains pointed to a distinct biosynthetic pathway, different from that of common fatty acids, because one or two C3 starter units are incorporated during the biosynthesis of all acid and alcohol building blocks present in the five esters. The striking sexual dimorphism together with the unique biosynthesis points to a function of the esters in chemical communication of the spiders, although no behavioral data are currently available to test this assumption.
Four New Diterpenoids from the Roots of Euphorbia pekinensis
Authors: Tian Rui‐Ying , Lu Yan , Chen Dao‐Feng
Published: July 2016

Three new isopimarane diterpenoids (1 – 3) and one new abietane diterpenoid (4) were isolated and identified from the roots of Euphorbia pekinensis, together with four known diterpenoids. Their structures were elucidated on the basis of extensive spectroscopic methods (IR, MS, NMR, and CD), and their cytotoxicities and anticomplement activities were evaluated.
Three New Ergot Alkaloids from the Fruiting Bodies of Xylaria nigripes (Kl.) Sacc.
Authors: Hu Dongbao , Li Ming
Published: July 2016

Three new ergot alkaloids, xylanigripones A – C (1 – 3) together with three known compounds, agroclavine (4), 8,9‐didehydro‐10‐hydroxy‐6,8‐dimethylergolin (5), and (6S)‐agroclavine N‐oxide (6) were isolated from the fungus Xylaria nigripes (Kl.) Sacc. Their structures were elucidated by comprehensive spectroscopic analyses and high‐resolution mass spectrometry as well as by comparison with the literature. The absolute configuration was determined by Density Functional Theory (DFT) calculation methods. In addition, all of the compounds were evaluated for bioactivity via a cytotoxicity assay, an acetylcholinesterase inhibition assay and a cholesterol ester transfer protein inhibition assay.
Triterpenoid Saponins with Potential Cytotoxic Activities from the Root Bark of Ilex rotunda Thunb.
Authors: Liu Wei‐Jie , Peng Yu‐Yuan , Chen Hao , Liu Xian‐Fang , Liang Jing‐Yu , Sun Jian‐Bo
Published: July 2016

A new 19‐oxo‐18,19‐seco‐ursane‐type triterpeonoid saponin, laevigin E (8), together with 17 known compounds (1 – 7 and 9 – 18) were isolated from the root bark of Ilex rotunda Thunb. Their structures were determined by various spectroscopic analysis. Among them, compounds 6, 9, 11, and 18 were isolated from this species for the first time, while compounds 10 and 12 were firstly isolated from the family Aquifoliaceae. Biological activity assay showed that all triterpenoids exhibit moderate cytotoxic activities against MCF7, A549, HeLa and LN229 cell lines. The four triterpenoid saponins (3, 4, 6, and 8) exhibit slightly better activities compared to the four triterpenoid sapogenins (1, 2, 5, and 7). Compound 8 showed the best cytotoxicity against A549, HeLa and LN229 cell lines with IC50 of 17.83, 22.58 and 30.98 μm, respectively.
An Activator of an Adenylation Domain Revealed by Activity but Not Sequence Homology
Authors: Saha Shalini , Rokita Steven E.
Published: July 2016

Nonribosomal peptide synthetases (NRPSs), which are responsible for synthesizing many medicinally important natural products, frequently use adenylation domain activators (ADAs) to promote substrate loading. Although ADAs are usually MbtH‐like proteins (MLPs), a new type of ADA appears to promote an NRPS‐dependent incorporation of a dihydropyrrole unit into sibiromycin. The adenylation and thiolation didomain of the NRPS SibD catalyzes the adenylation of a limited number of amino acids including l‐Tyr, the precursor in dihydropyrrole biosynthesis, as determined by a standard radioactivity exchange assay. LC‐MS/MS analysis confirmed loading of l‐Tyr onto the thiolation domain. SibB, a small protein with no prior functional assignment or sequence homology to MLPs, was found to promote the exchange activity. MLPs from bacteria expressing homologous biosynthetic pathways were unable to replace this function of SibB. The discovery of this new type of ADA demonstrates the importance of searching beyond the conventional MLP standard for proteins affecting NRPS activity.
Biosynthetic Gene Cluster for Surugamide A Encompasses an Unrelated Decapeptide, Surugamide F
Authors: Ninomiya Akihiro , Katsuyama Yohei , Kuranaga Takefumi , Miyazaki Masayuki , Nogi Yuichi , Okada Shigeru , Wakimoto Toshiyuki , Ohnishi Yasuo , Matsunaga Shigeki , Takada Kentaro
Published: July 2016

Genome mining is a powerful method for finding novel secondary metabolites. In our study on the biosynthetic gene cluster for the cyclic octapeptides surugamides A–E (inhibitors of cathepsin B), we found a putative gene cluster consisting of four successive non‐ribosomal peptide synthetase (NRPS) genes, surA, surB, surC, and surD. Prediction of amino acid sequence based on the NRPSs and gene inactivation revealed that surugamides A–E are produced by two NRPS genes, surA and surD, which were separated by two NRPS genes, surB and surC. The latter genes are responsible for the biosynthesis of an unrelated peptide, surugamide F. The pattern of intercalation observed in the sur genes is unprecedented. The structure of surugamide F, a linear decapeptide containing one 3‐amino‐2‐methylpropionic acid (AMPA) residue, was determined by spectroscopic methods and was confirmed by solid‐phase peptide synthesis.
Design of Raspberry‐Shaped Microcarriers with Adjustable Protrusions and Functional Groups for the Improvement of Lipase Immobilization and Biocatalysis: Environmentally Friendly Esterification of Oleic Acid for Biodiesel
Authors: Tian Lei , Zhao Panpan , Li Xue , Ali Zafar , Li Xiangjie , Zhang Baoliang , Zhang Hepeng , Zhang Qiuyu
Published: July 2016

Raspberry‐shaped microparticles with adjustable protrusions and functional groups were synthesized and applied as carriers for the immobilization of lipase. The structural advantages of the raspberry‐shaped microcarriers with immobilized lipase (RM‐IL) are not only that the protrusions are constructed to play the role of a spacer arm, but the block structure enhances the bioactivity of lipase at the oil–water interface. The activation method used for the carrier has a significant effect on the performance of immobilized lipase. RM‐IL prepared by carboxylic acid activation has a 3.5‐fold increase of activity compared with that from amine activation and generates a fourfold increase of protein bound to 164 mg g−1 of carrier. Finally, RM‐IL is used as an environmentally friendly and high‐efficiency biocatalyst to catalyze the esterification of oleic acid for biodiesel under mild conditions, and the conversion can reach up to 82.1 %. Above all, raspberry‐shaped microcarriers prepared by an improved seed emulsion polymerization have prospects for industrialization.
Iodine as a Temperature‐Responsive Redox Shuttle Additive for Swelling Suppression of Lithium‐Ion Batteries at Elevated Temperatures
Authors: Park Seong‐Hyo , Kim Hyeon Jin , Jeon Joomi , Choi Yongsu , Cho Jeong‐Ju , Lee Hochun
Published: July 2016

The swelling issue by gas evolution at elevated temperatures (85–90 °C) is one of the major challenges related to current Li‐ion batteries (LIBs). We herein demonstrate that iodine (I2) as a redox shuttle additive, when its dose is properly determined, can suppress the swelling behavior of LiCoO2/graphite Al‐pouch cells during storage at 90 °C without sacrificing other cell performances. This approach is based on two findings: 1) swelling during 90 °C storage is severe only when the cells are fully charged, and 2) the shuttling reaction of I2 can be tuned to be activated only when the temperature is as high as 90 °C by employing an appropriate amount of I2. Therefore, when a fully charged cell is exposed to a temperature of 90 °C, the self‐discharge by I2 lowers the state of charge of the cell, suppressing the swelling. This temperature‐responsive shuttling behavior of I2 is ascribed to the preferential adsorption of I2 on the cathode surface. It is also confirmed that inclusion of the I2 additive does not lead to deterioration in other aspects of cell performance, such as the discharge capacity or long‐term cyclability. Along with the improved cell performance, the low‐cost and environmental compatibility of I2 makes it a promising electrolyte additive for thermally robust LIBs.
Chiral Heteroditopic Baskets Designed from Triazolated Calixarenes and Short Peptides
Authors: Gorbunov Alexander , Sokolova Nadezhda , Kudryashova Elena , Nenajdenko Valentine , Kovalev Vladimir , Vatsouro Ivan
Published: July 2016

Cone calix[4]arenes and calix[6]arenes bearing two, three, and four short peptide units each having two chiral carbon atoms were prepared. The syntheses were performed by using an efficient modular approach that includes the Ugi preparation of the azido‐peptide followed by its reactions with the propargylated calixarenes under CuAAC (CuI‐catalyzed azide–alkyne cycloaddition) conditions. The three novel multitopic hosts were probed for their ability to bind metal ions by UV titration, and showed the highest complexation efficiency towards copper(II) and lead(II). These two cations possessed quite different complexation modes with copper(II) bound predominantly by multiple‐triazole sites, in contrast to lead(II), which is stabilized mainly by multiple interactions with amide groups of the peptide units. Circular dichroism data for the free chiral hosts, their equimolar mixtures with copper(II) perchlorate and lead(II) perchlorate, and for tertiary mixtures of all three compounds showed the formation of mono‐ and binuclear complexes, or a switching behavior, depending on the structure of the host and the addition order of the cations.
ChemInform Abstract: The Isotypic Family of the Diarsenates MM′As2O7 (M: Sr, Ba; M′: Cd, Hg).
Authors: Weil Matthias
Published: July 2016

MM′As2O7 (M: Sr, Ba; M′: Cd, Hg) are prepared by hydrothermal reaction of As2O5, SrCO3 or Ba(OH)2, and HgO or CdO (autoclave, 190 or 220 °C °C, 4—5 d).
ChemInform Abstract: Crystal Structure and Luminescence Properties of Bi3+ Activated Ca2Y8(SiO4)6O2 Phosphors under Near UV Excitation.
Authors: Sun Zhihua , Wang Minqiang , Yang Zhi , Liu Kaiping , Zhu Feiyan
Published: July 2016

Oxyapatite Ca2Y8‐x (SiO4)6O2:xBi3+ (x = 0—2.5) phosphors are prepared by sintering stoichiometric mixtures of CaCO3, H2SiO3, Y2O3, and Bi2O3 in air (1400 °C, 6 h).
ChemInform Abstract: Defect‐Controlled Formation of Triclinic Na2CoP2O7 for 4 V Sodium‐Ion Batteries.
Authors: Kim Heejin , Park Chan Sun , Choi Jang Wook , Jung Yousung
Published: July 2016

Introduction of sodium deficiencies stabilizes the triclinic phase of Na2CoP2O7 over its other polymorphs.
ChemInform Abstract: Photofixation of Atmospheric Nitrogen to Ammonia with a Novel Ternary Metal Sulfide Catalyst under Visible Light.
Authors: Cao Yuhui , Hu Shaozheng , Li Fayun , Fan Zhiping , Bai Jin , Lu Guang , Wang Qiong
Published: July 2016

The new photocatalyst Mo0.1Ni0.1Cd0.8S is prepared from aqueous solutions of (NH4)2MoO4, Ni(NO3)2, Cd(OAc)2, and Na2S (autoclave, 160 °C, 16 h).
ChemInform Abstract: Catalytic Asymmetric Detrifluoroacetylative Aldol Reactions of Aliphatic Aldehydes for Construction of C‐F Quaternary Stereogenic Centers.
Authors: Zhang Lijun , Xie Chen , Dai Yanling , Mei Haibo , Han Jianlin , Soloshonokcd Vadim A. , Pan Yi
Published: July 2016

The asymmetric aldol addition reaction of aliphatic aldehydes with keto hydrates in presence of a copper‐chiral BOX ligand catalyst affords the products with high enantioselectivities.
ChemInform Abstract: An Efficient Synthesis of 1‐(4H‐1,2,4‐Triazol‐3‐yl)‐hexahydroquinoline‐3‐carbonitrile and Their Spiro Derivatives from β‐Enaminones.
Authors: Abdelhamid Ismail A. , Soliman Ghozlan Said A. , Abdelmoniem Doaa M. , Mady Mohamed F. , Abdelmoniem Amr M.
Published: July 2016

Cyclic enamines bearing a triazole ring undergo simple and facile Michael addition reactions with various arylidenemalononitriles or oxindoles affording the title hydroquinoline carbonitriles or spirooxindole derivatives, respectively.