bluuebunny/crossref_metadata_2025 huggingface dataset:
The tectonic history of the Niğde‐Kırşehir Massif and the Taurides since the Late Mesozoic: Paleomagnetic evidence for two‐phase orogenic curvature in Central Anatolia
Authors: Çinku Mualla Cengiz , Hisarli Z. Mümtaz , Yılmaz Yücel , Ülker Beyza , Kaya Nurcan , Öksüm Erdinç , Orbay Naci , Özbey Zeynep Üçtaş
Published: January 2016

The Niğde‐Kırşehir Massif, known also as the Central Anatolian Block, is bordered by the sutures of the Neotethys Ocean. The massif suffered several deformation phases during and after the consumption of the surrounding oceans and the postcollisional events of the continental pieces of Anatolia in latest Cretaceous to Miocene. Previous paleomagnetic studies on the Niğde‐Kırşehir Massif and its surroundings displayed either insufficient data or have claimed large rotations and/or remagnetization. In order to understand the tectonic history of the Niğde‐Kırşehir Massif and its adjacent blocks we have sampled 147 different sites in the age range of Upper Jurassic to Miocene from the Niğde‐Kırşehir Massif throughout its W/SW and E/SE boundaries and the central‐southeastern Taurides. The results display that except the limestones in central Taurides, all rocks examined carry a primary magnetization. Among these an important finding is that rotations between the massif and the central‐eastern Taurides indicate an oroclinal bending with counterclockwise rotation of R = 41.1° ± 7.6° in the SE and clockwise rotation of R = 45.9° ± 9.3° in the central Taurides from Upper Cretaceous rocks with respect to the African reference direction. Paleomagnetic rotations in the SE Taurides are compatible with the vergent direction of the thrusts generated from consumption of the Intra‐Tauride Ocean prior to postcollisional convergence between Taurides and the massif. In the central Taurides it has been shown that the clockwise rotation of 45.9 ± 9.3 started in Middle Eocene, because of a remagnetization in Upper Cretaceous limestones. The deformation was linked to the final closure of the southern Neotethys and the collision between the African and Eurasian plates. In the Niğde‐Kırşehir Massif counterclockwise rotation up to 25.5° ± 7.3° is recognized during Middle Eocene and interpreted in terms of block rotation together with the Taurides. After the Miocene a counterclockwise rotation of 16.8° ± 3.9° along the Eastern Taurides shows that this area was mostly affected by the westward movement of Anatolia despite the Niğde‐Kırşehir Massif and its SW/W area—the central Taurides—which is recognized as stable with counterclockwise rotation less than 10°.
Two‐phase convective CO2 dissolution in saline aquifers
Authors: Martinez M. J. , Hesse M. A.
Published: January 2016

Geologic carbon storage in deep saline aquifers is a promising technology for reducing anthropogenic emissions into the atmosphere. Dissolution of injected CO2 into resident brines is one of the primary trapping mechanisms generally considered necessary to provide long‐term storage security. Given that diffusion of CO2 in brine is woefully slow, convective dissolution, driven by a small increase in brine density with CO2 saturation, is considered to be the primary mechanism of dissolution trapping. Previous studies of convective dissolution have typically only considered the convective process in the single‐phase region below the capillary transition zone and have either ignored the overlying two‐phase region where dissolution actually takes place or replaced it with a virtual region with reduced or enhanced constant permeability. Our objective is to improve estimates of the long‐term dissolution flux of CO2 into brine by including the capillary transition zone in two‐phase model simulations. In the fully two‐phase model, there is a capillary transition zone above the brine‐saturated region over which the brine saturation decreases with increasing elevation. Our two‐phase simulations show that the dissolution flux obtained by assuming a brine‐saturated, single‐phase porous region with a closed upper boundary is recovered in the limit of vanishing entry pressure and capillary transition zone. For typical finite entry pressures and capillary transition zone, however, convection currents penetrate into the two‐phase region. This removes the mass transfer limitation of the diffusive boundary layer and enhances the convective dissolution flux of CO2 more than 3 times above the rate assuming single‐phase conditions.
NMR study comparing capillary trapping in Berea sandstone of air, carbon dioxide, and supercritical carbon dioxide after imbibition of water
Authors: Prather Cody A. , Bray Joshua M. , Seymour Joseph D. , Codd Sarah L.
Published: January 2016

Nuclear magnetic resonance (NMR) techniques were used to study the capillary trapping mechanisms relevant to carbon sequestration. Capillary trapping is an important mechanism in the initial trapping of supercritical CO2 in the pore structures of deep underground rock formations during the sequestration process. Capillary trapping is considered the most promising trapping option for carbon sequestration. NMR techniques noninvasively monitor the drainage and imbibition of air, CO2, and supercritical CO2 with DI H2O at low capillary numbers in a Berea sandstone rock core under conditions representative of a deep underground saline aquifer. Supercritical CO2 was found to have a lower residual nonwetting (NW) phase saturation than that of air and CO2. Supercritical CO2 behaves differently than gas phase air or CO2 and leads to a reduction in capillary trapping. NMR relaxometry data suggest that the NW phase, i.e., air, CO2, or supercritical CO2, is preferentially trapped in larger pores. This is consistent with snap‐off conditions being more favorable in macroscale pores, as NW fluids minimize their contact area with the solid and hence prefer larger pores.
Heavy Metals
Authors: Aydın Ahmet Alper , Aydın Adnan
Published: January 2016

Heavy metals in combustible materials such as fossil fuels, biomass, municipal and medical wastes, sewage sludges, and in industrial wastes such as slags, are important pollutants for the environment. The bottom ashes and fly ashes from the combustion and incineration processes contain heavy metals as enrichment products in significant ratios. Therefore, heavy‐metal enrichment after combustion and incineration processes have been extensively discussed in this chapter. The health effects of heavy metals are described, with special attention paid to safe use of the combustion and incineration residues and fly ashes. The utilization of residues and fly ashes in cement production, soil remediation, adsorption of different pollutants and heavy metal recovery are outlined, as well as the stabilization/solidification of ashes and slags.
False Memories for an Analogue Trauma: Does Thought Suppression Help or Hinder Memory Accuracy?
Authors: Oulton Jacinta M. , Strange Deryn , Takarangi Melanie K.T.
Published: January 2016

In the current study, we investigated whether suppression can produce an amplified memory for a traumatic experience. Participants viewed a distressing film depicting a multi‐fatality car accident. We broke the film down into several short clips, some of which were removed. After viewing the film, we instructed participants to (i) suppress and monitor film‐related thoughts, (ii) think freely and monitor film‐related thoughts or (iii) just think freely. Twenty‐four hours later, participants completed a recognition test. Memory distortion was comparable across conditions; however, suppression and monitoring of trauma‐related thoughts removed the typical bias to falsely remember the most critical and traumatic clips of the film over the least critical clips. Our data suggest that suppression may be effective in reducing trauma‐related cognitions and, therefore, does not predict a more ‘amplified’ memory for trauma. Instead, suppression and thought monitoring encourage an unbiased, although inaccurate, memory for trauma.Copyright © 2016 John Wiley & Sons, Ltd.
Ionic Liquid‐Assisted Synthesis of TiO2–Carbon Hybrid Nanostructures for Lithium‐Ion Batteries
Authors: Cheng Yanhua , Chen Zheng , Wu Haobin , Zhu Meifang , Lu Yunfeng
Published: January 2016

Building nanocomposite architectures based on nanocarbon materials (such as carbon nanotubes and graphene nanosheets) and metal‐oxide nanoparticles is of great interests for electrochemical energy storage. Here, an ionic‐liquid‐assisted strategy is presented to mediate the in situ growth of TiO2 nanocrystals with controlled size on carbon nanotubes and graphene, and also reduce the modified carbon supports to recover the graphitic structure simultaneously. The as‐prepared nanocomposites exhibit a highly porous and robust structure with intimate coupling between TiO2 nanocrystals and carbon supports, which offers facile ion and electron transport pathway as well as high mechanical stability. When evaluated as electrode materials for lithium‐ion batteries, the nanocomposites manifest high specific capacity, long cycling lifetime, and excellent rate capability, showing their promising application in high‐performance energy storage devices.
A Self‐Powered and Stable All‐Perovskite Photodetector–Solar Cell Nanosystem
Authors: Lu Hao , Tian Wei , Cao Fengren , Ma Yulong , Gu Bangkai , Li Liang
Published: January 2016

Hybrid organic–inorganic perovskites have attracted intensive interest as light absorbing materials in solid‐state solar cells. Herein, we demonstrate a high‐performance CH3NH3PbI3‐based perovskite photodetector constructed on the flexible indium tin oxide (ITO) coated substrate even after 200 bending cycles. The as‐fabricated devices show high responsivity, broad spectrum response from ultraviolet to whole visible light, long‐term stability, and high on‐off ratio. Particularly, atomic layer deposition technique was used to deposit the ultrathin Al2O3 film on devices, functioning as a protection layer to effectively enhance the stability and durability of perovskite photodetectors. The first all‐perovskite self‐powered nanosystem was successfully assembled by integrating a perovskite solar cell with a perovskite photodetector. Driven by the perovskite solar cell, the photodetector exhibits fast and stable response to illuminated light at a low working voltage less than 1.0 V. This stable integrated nanosystem has promising applications in which photodetectors can work in harsh environments without external power sources.
Recent Advances in Flexible and Stretchable Bio‐Electronic Devices Integrated with Nanomaterials
Authors: Choi Suji , Lee Hyunjae , Ghaffari Roozbeh , Hyeon Taeghwan , Kim Dae‐Hyeong
Published: January 2016

Flexible and stretchable electronics and optoelectronics configured in soft, water resistant formats uniquely address seminal challenges in biomedicine. Over the past decade, there has been enormous progress in the materials, designs, and manufacturing processes for flexible/stretchable system subcomponents, including transistors, amplifiers, bio‐sensors, actuators, light emitting diodes, photodetector arrays, photovoltaics, energy storage elements, and bare die integrated circuits. Nanomaterials prepared using top‐down processing approaches and synthesis‐based bottom‐up methods have helped resolve the intrinsic mechanical mismatch between rigid/planar devices and soft/curvilinear biological structures, thereby enabling a broad range of non‐invasive, minimally invasive, and implantable systems to address challenges in biomedicine. Integration of therapeutic functional nanomaterials with soft bioelectronics demonstrates therapeutics in combination with unconventional diagnostics capabilities. Recent advances in soft materials, devices, and integrated systems are reviewes, with representative examples that highlight the utility of soft bioelectronics for advanced medical diagnostics and therapies.
Bio‐Nano‐Magnetic Materials for Localized Mechanochemical Stimulation of Cell Growth and Death
Authors: Kilinc Devrim , Dennis Cindi L. , Lee Gil U.
Published: January 2016

Magnetic nanoparticles are promising new tools for therapeutic applications, such as magnetic nanoparticle hyperthermia therapy and targeted drug delivery. Recent in vitro studies have demonstrated that a force application with magnetic tweezers can also affect cell fate, suggesting a therapeutic potential for magnetically modulated mechanical stimulation. The magnetic properties of nanoparticles that induce physical responses and the subtle responses that result from mechanically induced membrane damage and/or intracellular signaling are evaluated. Magnetic particles with various physical, geometric, and magnetic properties and specific functionalization can now be used to apply mechanical force to specific regions of cells, which permit the modulation of cellular behavior through the use of spatially and time controlled magnetic fields. On one hand, mechanochemical stimulation has been used to direct the outgrowth on neuronal growth cones, indicating a therapeutic potential for neural repair. On the other hand, it has been used to kill cancer cells that preferentially express specific receptors. Advances made in the synthesis and characterization of magnetic nanomaterials and a better understanding of cellular mechanotransduction mechanisms may support the translation of mechanochemical stimulation into the clinic as an emerging therapeutic approach.
Underwater Superoleophobic Surfaces Prepared from Polymer Zwitterion/Dopamine Composite Coatings
Authors: Chang Chia‐Chih , Kolewe Kristopher W. , Li Yinyong , Kosif Irem , Freeman Benny D. , Carter Kenneth R. , Schiffman Jessica D. , Emrick Todd
Published: January 2016

Hydration is central to mitigating surface fouling by oil and microorganisms. Immobilization of hydrophilic polymers on surfaces promotes retention of water and a reduction of direct interactions with potential foulants. While conventional surface modification techniques are surface‐specific, mussel‐inspired adhesives based on dopamine effectively coat many types of surfaces and thus hold potential as a universal solution to surface modification. Here, a facile, one‐step surface modification strategy is described that affords hydrophilic, and underwater superoleophobic, coatings by the simultaneous deposition of polydopamine (PDA) with poly(methacryloyloxyethyl phosphorylcholine) (polyMPC). The resultant composite coating features enhanced hydrophilicity (i.e., water contact angle of ≈10° in air) and antifouling performance relative to PDA coatings. PolyMPC affords control over coating thickness and surface roughness and results in a nearly tenfold reduction in Escherichia coli adhesion relative to unmodified glass. The substrate‐independent nature of PDA coatings further promotes facile surface modification without tedious surface pretreatment and offers a robust template for codepositing polyMPC to enhance biocompatibility, hydrophilicity, and fouling resistance.
Catalysis by β‐Cyclodextrin Hydrate – Synthesis of 2,2‐Disubstituted 2H‐Chromenes in Aqueous Medium
Authors: Ghatak Avishek , Khan Sagar , Bhar Sanjay
Published: January 2016

A cost‐effective, operationally simple and eco‐compatible protocol for the one‐pot synthesis of photochromic pyrans by the reaction of propargyl alcohols as well as propargyl ethers with differently substituted phenols under ambient atmosphere in aqueous medium has been developed using β‐cyclodextrin hydrate as an efficient, recyclable and stable catalyst. This is the first report where β‐cyclodextrin hydrate acted as a catalyst for an organic transformation but β‐cyclodextrin alone failed.

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Synthesis of 3,3‐Disubstituted Oxindoles Containing a 3‐(4‐Aminobut‐2‐ynyl) Unit via Domino Heck–Sonogashira Reaction in Water
Authors: Wang Dong‐Chao , Wang Hai‐Xia , Hao Er‐Jun , Jiang Xiao‐Han , Xie Ming‐Sheng , Qu Gui‐Rong , Guo Hai‐Ming
Published: January 2016

In this study, palladium‐catalyzed domino Heck–Sonogashira reactions have been developed in water. Using this strategy, a series of 3‐(4‐aminobut‐2‐ynyl)oxindole derivatives with an all‐carbon quaternary center at the 3‐position were easily synthesized. The reactions provided products in excellent yields with a broad substrate tolerance. The target product was readily converted into a pharmaceutically active molecule, which is used as a 5‐HT7 receptor antagonist.

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CH Functionalization/CO Bond Cleavage of Benzyl Silyl Ethers with Ynamides for the Chemoselective Synthesis of Skeletally Diverse Compounds
Authors: Chen Ling , Yu Lian , Deng Yuan , Zheng Zhan‐Jiang , Xu Zheng , Cao Jian , Xu Li‐Wen
Published: January 2016

Described here is a practical carbocation‐initiated formal [3+2] or [4+2] cycloaddition reaction for the diversity‐oriented syntheses of 1‐amidoindenes and 2‐amido‐4H‐chromenes. The Lewis acid‐promoted annulation of ynamides and benzyl silyl ethers efficiently constructs 1‐amidoindenes via CH functionalization of benzyl silyl ethers. By utilization of o‐methoxybenzyl silyl ethers, 2‐amido‐4H‐chromenes are also constructed via CO bond cleavage of benzyl silyl ethers.

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Direct Synthesis of Primary Amines via Ruthenium‐Catalysed Amination of Ketones with Ammonia and Hydrogen
Authors: Gallardo‐Donaire Joan , Ernst Martin , Trapp Oliver , Schaub Thomas
Published: January 2016

A highly selective reductive amination of ketones to primary amines with ammonia and hydrogen using a simple ruthenium catalyst has been developed. The protocol described constitutes an efficient and direct atom‐economical approach en route to α‐methylbenzylamine derivatives in good to high yields. The presence of catalytic amounts of aluminum triflate turned out to be crucial for achieving high conversion towards primary amines.

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Synthesis and Characterization of Poly[dimethylacrylamide‐co‐allyl acetoacetate] Grafted to Zinc Oxide Nanoparticles for Preconcentration and Determination of Cadmium Ions in Biological and Environmental Samples
Authors: Panahi Homayon Ahmad , Nasrollahi Sara , Fouladlou Somayeh , Moniri Elham
Published: January 2016

In this paper, a method is designed for surface grafting of polymer containing a functional monomer for metal chelating, poly[dimethylacrylamide‐co‐allyl acetoacetate] (poly[DMAA‐co‐AA]) onto zinc oxide nanoparticles modified by 3‐mercaptopropyltrimethoxysilane. The resulting nanosorbent was characterized using Fourier transform infrared spectroscopy, elemental analysis, thermogravimetric analysis, scanning electron microscopy, and transmission electron microscopy. The preconcentration and determination of trace amount of Cd(II) ions was evaluated in human biological fluid, environmental water samples, and milk. The optimum pH value for sorption of the metal ion was 6. The sorption capacity of grafted sorbent was 46.1 mg g−1. A high recovery of Cd(II) ions was in the range of 95–103% with 1 M hydrochloric acid as eluting factor. The profile of cadmium uptake by the nanosorbent indicated high accessibility of active chelating sites in poly[DMAA‐co‐AA]‐grafted modified zinc oxide nanoparticles. The equilibrium adsorption data of Cd(II) by synthesized sorbent were investigated by Langmuir, Freundlich, Temkin, and Redlich–Peterson models.
From Playroom to Lab: Tough Stretchable Electronics Analyzed with a Tabletop Tensile Tester Made from Toy‐Bricks
Authors: Moser Richard , Kettlgruber Gerald , Siket Christian M. , Drack Michael , Graz Ingrid M. , Cakmak Umut , Major Zoltan , Kaltenbrunner Martin , Bauer Siegfried
Published: January 2016

Toy bricks are an ideal platform for the cost‐effective rapid prototyping of a tabletop tensile tester with measurement accuracy on par with expensive, commercially available laboratory equipment. Here, a tester is presented that is not only a versatile demonstration device in mechanics, electronics, and physics education and an eye‐catcher on exhibitions, but also a powerful tool for stretchable electronics research. Following the “open‐source movement” the build‐up of the tester is described and all the details for easy reproduction are disclosed. A a new design of highly conformable all‐elastomer based graded rigid island printed circuit boards is developed. Tough bonded to this elastomer substrate are imperceptible electronic foils bearing conductors and off‐the‐shelf microelectronics, paving the way for next generation smart electronic appliances.
Is Excess PbI2 Beneficial for Perovskite Solar Cell Performance?
Authors: Liu Fangzhou , Dong Qi , Wong Man Kwong , Djurišić Aleksandra B. , Ng Annie , Ren Zhiwei , Shen Qian , Surya Charles , Chan Wai Kin , Wang Jian , Ng Alan Man Ching , Liao Changzhong , Li Hangkong , Shih Kaimin , Wei Chengrong , Su Huimin , Dai Junfeng
Published: January 2016

Unreacted lead iodide is commonly believed to be beneficial to the efficiency of methylammonium lead iodide perovskite based solar cells, since it has been proposed to passivate the defects in perovskite grain boundaries. However, it is shown here that the presence of unreacted PbI2 results in an intrinsic instability of the film under illumination, leading to the film degradation under inert atmosphere and faster degradation upon exposure to illumination and humidity. The perovskite films without lead iodide have improved stability, but lower efficiency due to inferior film morphology (smaller grain size, the presence of pinholes). Optimization of the deposition process resulted in PbI2‐free perovskite films giving comparable efficiency to those with excess PbI2 (14.2 ± 1.3% compared to 15.1 ± 0.9%) Thus, optimization of the deposition process for PbI2‐free films leads to dense, pinhole‐free, large grain size perovskite films which result in cells with high efficiency without detrimental effects on the film photostability caused by excess PbI2. However, it should be noted that for encapsulated devices illuminated through the substrate (fluorine‐doped tin oxide glass, TiO2 film), film photostability is not a key factor in the device degradation.
Salivary but not blood cortisol excretion is associated with metabolic biomarkers in healthy young women
Authors: Konishi Shoko , O'Connor Kathleen A.
Published: January 2016

Objectives

Elevated and suppressed concentrations of cortisol have been linked with less favorable metabolic biomarkers, such as elevated lipids and glycosylated hemoglobin (HbA1c). Based on recent work reporting that some individuals secrete more cortisol into saliva (high saliva‐to‐blood cortisol ratio; high secretors) than others after correcting for blood cortisol concentrations, our objectives were to examine (1) whether lipids and glycosylated hemoglobin varied across cortisol and salivary secretor status; and (2) if blood and saliva provide the same results with respect to metabolic markers.

Methods

Matched saliva and dried blood spot (DBS) specimens collected once a week for four weeks (N = 48 healthy women, 192 specimens) were assayed for cortisol. Fasting blood specimens collected once from each woman were quantified for cholesterol (total, HDL, LDL), triglycerides and HbA1c.

Results

Low salivary cortisol secretors showed significantly higher triglyceride and HbA1c compared to high‐secretors (P<0.05; t‐test). The only significant correlation with mean blood or salivary cortisol concentration was a negative correlation between salivary cortisol and HbA1c (P = 0.021, r = −0.333).

Conclusions

Triglycerides, HDL, and especially HbA1c were associated with salivary cortisol secretor status but not with DBS cortisol concentrations. These results suggest that blood and saliva cortisol measures might provide different health outcome information, and that salivary cortisol secretor status may provide additional information on health status. Am. J. Hum. Biol. 28:539–544, 2016. © 2016 Wiley Periodicals, Inc.
The Regioselectivity of Bingel–Hirsch Cycloadditions on Isolated Pentagon Rule Endohedral Metallofullerenes
Authors: Garcia‐Borràs Marc , Cerón Maira R. , Osuna Sílvia , Izquierdo Marta , Luis Josep M. , Echegoyen Luis , Solà Miquel
Published: January 2016

In this work, the Bingel–Hirsch addition of diethylbromomalonate to all non‐equivalent bonds of Sc3N@D3h‐C78 was studied using density functional theory calculations. The regioselectivities observed computationally allowed the proposal of a set of rules, the predictive aromaticity criteria (PAC), to identify the most reactive bonds of a given endohedral metallofullerene based on a simple evaluation of the cage structure. The predictions based on the PAC are fully confirmed by both the computational and experimental exploration of the Bingel–Hirsch reaction of Sc3N@D5h‐C80, thus indicating that these rules are rather general and applicable to other isolated pentagon rule endohedral metallofullerenes.
Spontaneous Capture of Carbohydrate Guests through Folding and Zipping of Self‐Assembled Ribbons
Authors: Shen Bowen , He Ying , Kim Yongju , Wang Yanqiu , Lee Myongsoo
Published: January 2016

One of the great challenges in molecular self‐assembly is how to confer self‐folding and closing characteristics on flat two‐dimensional structures in response to external triggers. Herein, we report a planar ribbon assembly that folds into closed tubules in response to fructose. The ribbons, ≈28 nm wide and 3.5 nm thick, consist of 8 laterally‐associated elementary fibrils in which disc‐shaped macrocycle amphiphiles are stacked along their axis. Upon addition of fructose, these flat structures spontaneously fold into closed tubules, with an outer diameter of ≈8 nm, through zipping of the two sides of the ribbons. Notably, the folding and then zipping of the flat ribbons is accompanied by spontaneous capture of the fructose molecules inside the tubular cavities.
Single Lithium‐Ion Conducting Polymer Electrolytes Based on a Super‐Delocalized Polyanion
Authors: Ma Qiang , Zhang Heng , Zhou Chongwang , Zheng Liping , Cheng Pengfei , Nie Jin , Feng Wenfang , Hu Yong‐Sheng , Li Hong , Huang Xuejie , Chen Liquan , Armand Michel , Zhou Zhibin
Published: January 2016

A novel single lithium‐ion (Li‐ion) conducting polymer electrolyte is presented that is composed of the lithium salt of a polyanion, poly[(4‐styrenesulfonyl)(trifluoromethyl(S‐trifluoromethylsulfonylimino)sulfonyl)imide] (PSsTFSI−), and high‐molecular‐weight poly(ethylene oxide) (PEO). The neat LiPSsTFSI ionomer displays a low glass‐transition temperature (44.3 °C; that is, strongly plasticizing effect). The complex of LiPSsTFSI/PEO exhibits a high Li‐ion transference number (tLi+=0.91) and is thermally stable up to 300 °C. Meanwhile, it exhibits a Li‐ion conductivity as high as 1.35×10−4 S cm−1 at 90 °C, which is comparable to that for the classic ambipolar LiTFSI/PEO SPEs at the same temperature. These outstanding properties of the LiPSsTFSI/PEO blended polymer electrolyte would make it promising as solid polymer electrolytes for Li batteries.
Combining Metabolic Engineering and Electrocatalysis: Application to the Production of Polyamides from Sugar
Authors: Suastegui Miguel , Matthiesen John E. , Carraher Jack M. , Hernandez Nacu , Rodriguez Quiroz Natalia , Okerlund Adam , Cochran Eric W. , Shao Zengyi , Tessonnier Jean‐Philippe
Published: January 2016

Biorefineries aim to convert biomass into a spectrum of products ranging from biofuels to specialty chemicals. To achieve economically sustainable conversion, it is crucial to streamline the catalytic and downstream processing steps. In this work, a route that combines bio‐ and electrocatalysis to convert glucose into bio‐based unsaturated nylon‐6,6 is reported. An engineered strain of Saccharomyces cerevisiae was used as the initial biocatalyst for the conversion of glucose into muconic acid, with the highest reported muconic acid titer of 559.5 mg L−1 in yeast. Without any separation, muconic acid was further electrocatalytically hydrogenated to 3‐hexenedioic acid in 94 % yield despite the presence of biogenic impurities. Bio‐based unsaturated nylon‐6,6 (unsaturated polyamide‐6,6) was finally obtained by polymerization of 3‐hexenedioic acid with hexamethylenediamine.
Determination of the Absolute Configuration of the Pseudo‐Symmetric Natural Product Elatenyne by the Crystalline Sponge Method
Authors: Urban Sylvia , Brkljača Robert , Hoshino Manabu , Lee Shoukou , Fujita Makoto
Published: January 2016

Elatenyne is a marine natural product that was isolated in 1986. Despite its simple 2,2′‐bifuranyl backbone, its relative structure was only recently determined. The absolute configuration of elatenyne has still not been unequivocally confirmed because of its pseudo‐meso core structure, which results in a specific rotation, [α]D , of almost zero. In this work, the structure of natural elatenyne was determined by the crystalline sponge method and the use of a porous coordination network (a crystalline sponge) capable of absorbing organic guests; in the sponge, the absorbed guests are ordered and crystallographically observable. The crystalline sponge could differentiate between the two very similar alkyl side chains, and the absolute structure of elatenyne was thus reliably determined. The total amount required for the experiments was only approximately 100 μg, and the majority (95 μg) could be recovered after the experiments.
Refoldable Foldamers: Global Conformational Switching by Deletion or Insertion of a Single Hydrogen Bond
Authors: Le Bailly Bryden A. F. , Byrne Liam , Clayden Jonathan
Published: January 2016

Small changes in the structure of a foldamer may lead to gross changes in conformational preference. We show that the simple insertion or deletion of a single hydrogen bond by changes in pH or by photochemical deprotection is sufficient to refold a helical oligomer, interconverting M and P screw‐sense preference. As a consequence of the switch, information may be transmitted to a remote catalytic site, selectively directing the formation of either of two enantiomeric products by a reaction involving 1,22‐remote intermolecular asymmetric induction.
Practical Direct α‐Arylation of Cyclopentanones by Palladium/Enamine Cooperative Catalysis
Authors: Xu Yan , Su Tianshun , Huang Zhongxing , Dong Guangbin
Published: January 2016

Direct arylation of cyclopentanones has been a long‐standing challenge because of competitive self‐aldol condensation and multiple arylations. Reported herein is a direct mono‐α‐C−H arylation of cyclopentanones with aryl bromides which is enabled by palladium/amine cooperative catalysis. This method is scalable and chemoselective with broad functional‐group tolerance. Application to controlled sequential arylation of cyclopentanones has been also demonstrated.
Enantioselektive Totalsynthese der Terreumole A und C aus dem Pilz Tricholoma terreum
Authors: Frichert Alex , Jones Peter G. , Lindel Thomas
Published: January 2016

Erstmals gelang die enantioselektive Totalsynthese der cytotoxischen Meroterpenoide Terreumol A und C aus dem Gemeinen Erd‐Ritterling Tricholoma terreum. Schlüsselschritt ist der Aufbau des zehngliedrigen Rings durch Olefinmetathese zur trisubstituierten Z‐Doppelbindung des [8.4.0]‐Bicyclus, die nur in Abwesenheit freier Hydroxygruppen gelang. (−)‐Terreumol C wurde vollständig diastereoselektiv in das Bisepoxid (−)‐Terreumol A überführt, das somit ausgehend von 2‐Brom‐3,4‐dimethoxybenzaldehyd in 14 Stufen und einer Gesamtausbeute von 23 % erhalten wurde. Eine Röntgenstrukturanalyse des p‐Benzochinon‐Analogons von (−)‐Terreumol A bestätigt die absolute Konfiguration der Naturstoffe.
Unified Total Synthesis of 3‐epi‐Ryanodol, Cinnzeylanol, Cinncassiols A and B, and Structural Revision of Natural Ryanodol and Cinnacasol
Authors: Koshimizu Masaki , Nagatomo Masanori , Inoue Masayuki
Published: January 2016

Ryanodane diterpenoids structurally share an extremely complex fused ring system, but differ in the substitution patterns of the hydroxy groups. Since these congeners exhibit various biologically important functions, their efficient chemical constructions have been greatly anticipated. We previously accomplished the total synthesis of ryanodine (1) using pentacycle 8 as the advanced intermediate. Here, we report the unified total syntheses of four distinct diterpenoids, 3‐epi‐ryanodol (3), cinnzeylanol (4), cinncassiols B (5), and A (6), from 8, all within 10 steps. A series of highly optimized chemo‐ and stereoselective reactions and protecting‐group manipulations enabled assembly of the densely oxygenated structures of 3–6. Furthermore, the present synthetic studies established the C13S stereochemisty of 5–7 and revised the proposed structures of natural ryanodol (2) and cinnacasol (7) to be those of 3 and 6, respectively.
Direct Catalytic Synthesis of Unprotected 2‐Amino‐1‐Phenylethanols from Alkenes by Using Iron(II) Phthalocyanine
Authors: Legnani Luca , Morandi Bill
Published: January 2016

Aryl‐substituted amino alcohols are privileged scaffolds in medicinal chemistry and natural products. Herein, we report that an exceptionally simple and inexpensive FeII complex efficiently catalyzes the direct transformation of simple alkenes into unprotected amino alcohols in good yield and perfect regioselectivity. This new catalytic method was applied in the expedient synthesis of bioactive molecules and could be extended to aminoetherification.
Metal–Metal Interactions in Heterobimetallic Complexes with Dinucleating Redox‐Active Ligands
Authors: Broere Daniël L. J. , Modder Dieuwertje K. , Blokker Eva , Siegler Maxime A. , van der Vlugt Jarl Ivar
Published: January 2016

The tuning of metal–metal interactions in multinuclear assemblies is a challenge. Selective P coordination of a redox‐active PNO ligand to AuI followed by homoleptic metalation of the NO pocket with NiII affords a unique trinuclear Au–Ni–Au complex. This species features two antiferromagnetically coupled ligand‐centered radicals and a double intramolecular d8–d10 interaction, as supported by spectroscopic, single‐crystal X‐ray diffraction, and computational data. A corresponding cationic dinuclear Au–Ni analogue with a stronger d8–d10 interaction is also reported. Although both heterobimetallic structures display rich electrochemistry, only the trinuclear Au–Ni–Au complex facilitates electrocatalytic C−X bond activation of alkyl halides in its doubly reduced state. Hence, the presence of a redox‐active ligand framework, an available coordination site at gold, and the nature of the nickel–gold interaction appear to be essential for this reactivity.
Structurally Defined αMHC‐II Nanobody–Drug Conjugates: A Therapeutic and Imaging System for B‐Cell Lymphoma
Authors: Fang Tao , Duarte Joao N. , Ling Jingjing , Li Zeyang , Guzman Jonathan S. , Ploegh Hidde L.
Published: January 2016

Antibody–drug conjugates (ADCs) of defined structure hold great promise for cancer therapies, but further advances are constrained by the complex structures of full‐sized antibodies. Camelid‐derived single‐domain antibody fragments (VHHs or nanobodies) offer a possible solution to this challenge by providing expedited target screening and validation through switching between imaging and therapeutic activities. We used a nanobody (VHH7) specific for murine MHC‐II and rendered “sortase‐ready” for the introduction of oligoglycine‐modified cytotoxic payloads or NIR fluorophores. The VHH7 conjugates outcompeted commercial monoclonal antibodies (mAbs) for internalization and exhibited high specificity and cytotoxicity against A20 murine B‐cell lymphoma. Non‐invasive NIR imaging with a VHH7–fluorophore conjugate showed rapid tumor targeting on both localized and metastatic lymphoma models. Subsequent treatment with the nanobody–drug conjugate efficiently controlled tumor growth and metastasis without obvious systemic toxicity.
Selective Multiamination of C70 Leading to Curved π Systems with 60, 58, 56, and 50 π Electrons
Authors: Li Yanbang , Xu Dan , Gan Liangbing
Published: January 2016

Secondary aliphatic amines add to a pole pentagon of [70]fullerene in the presence of N‐fluorobenzenesulfonimide to form cyclopentadienyl‐type adducts, C70(NSO2Ph)(NR1R2)4 (1), which can be converted into analogous C70 derivatives such as C70(NHSO2Ph)(NHTol)5 (2). Further addition reactions of either 1 or 2 take place selectively at the opposite pole pentagon of the C70 cage, thus forming curved π systems with a reduced number of π electrons, and the products include a dodecakis‐adduct with a Vögtle belt motif.
Immobilization of a vanadium complex onto functionalized nanoporous MCM‐41 and its application as a catalyst for the solvent‐free chemoselective oxidation of sulfide to sulfoxide
Authors: Nikoorazm M. , Ghorbani‐Choghamarani A. , Khanmoradi M.
Published: January 2016

A complex moiety containing VO(IV) was anchored covalently into organic‐modified Si‐MCM‐41 to prepare a new catalyst. The prepared materials were characterized using various techniques. Several types of aromatic and aliphatic sulfides were successfully oxidized to the corresponding sulfoxides in good to excellent yields using H2O2 in the presence of a catalytic amount of the catalyst under solvent‐free conditions. The results showed that the OH groups of the various compounds such as 2,2‐(phenylthio)ethanol and 2‐(methylthio)ethanol remained intact under similar conditions. Meanwhile the catalyst was stable in the reaction system, and could be reused at least four times without significant loss of its activity and chemoselectivity. Copyright © 2016 John Wiley & Sons, Ltd.
Treatments of protein for biopolymer production in view of processability and physical properties: A review
Authors: Du Yicheng , Li Shuzhao , Zhang Yachuan , Rempel Curtis , Liu Qiang
Published: January 2016

The development of bio‐based polymers from proteins has gained attention for their large availability and renewable and biodegradable nature. However, protein‐based plastics have limited commercial applications because of several drawbacks, such as poor processability, brittleness, moisture sensitivity, and inferior mechanical and thermal properties. Extensive studies have been conducted to solve or ameliorate these issues by pretreatment or modification of proteins or protein‐derived biopolymers before or during wet processing or dry processing at elevated temperatures. This review provides an overview of research efforts conducted in the area of physical and chemical treatment of proteins to achieve better processability, mechanical properties, and other physical performance based on a literature review in this subject. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43351.
Synthesis and characterization of fluorine‐containing polyurethane–acrylate core–shell emulsion
Authors: Zhao Meng , Li Hui , Wen Lefei , Yu Zitian , Zhang Shuo , Han Zhewen
Published: January 2016

Fluorinated polyurethane–acrylate (FPUA) hybrid emulsion was prepared by copolymerization of polyurethane, methyl methacrylate, and 1H,1H,2H,2H‐heptadecafluorooctyl acrylate (FA) via emulsion polymerization in the presence of a perfluoronated reactive surfactant. The polyurethane was synthesized from isophorone diisocyanate, poly(propylene glycol)‐1000, dimethylolpropionic acid, 1,4‐butanediol, and 2‐hydroxyethyl methylacrylate. The influence of the monomer on the surface properties, wetting behaviors, particle size, and viscosity of the emulsion was investigated. The mechanical properties of FPUA latex films were improved, and water absorption and contact angle were improved with the addition of methyl methacrylate and FA. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 43357.
Synthesis and properties of click coupled graphene oxide sheets with three‐dimensional macromolecules
Authors: Mahapatra Sibdas Singha , Ramasamy Madeshwaran Sekkarapatti , Yoo Hye Jin , Yi Dong Hun , Cho Jae Whan
Published: January 2016

A facile click chemistry approach to the functionalization of three‐dimensional hyperbranched polyurethane (HPU) to graphene oxide (GO) nanosheets is presented. HPU‐functionalized GO samples of various compositions were synthesized by reacting alkyne‐functionalized HPU with azide‐functionalized GO sheets. The morphological characterization of the HPU‐functionalized GO was performed using transmission electron microscopy and its chemical characterization was carried out using Fourier transform‐infrared spectroscopy, nuclear magnetic resonance spectroscopy, and X‐ray photoelectron spectroscopy. The graphene sheet surfaces were highly functionalized, leading to improved solubility in organic solvents, and consequently, enhanced mechanical, thermal, and thermoresponsive and photothermal shape memory properties. The strategy reported herein provides a very efficient method for regulating composite properties and producing high performance materials. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43358.
Composite membranes of chitosan and titania‐coated carbon nanotubes as promising materials for new proton‐exchange membranes
Authors: Liu Hai , Wang Jie , Wen Sheng , Gong Chunli , Cheng Fan , Wang Guangjin , Zheng Genwen , Qin Caiqin
Published: January 2016

Titania‐coated carbon nanotubes (TCNTs) were obtained by a simple sol–gel method. Then chitosan/TCNT (CS/TCNT) composite membranes were prepared by stirring chitosan/acetic acid and a TCNT/ethanol suspension. The morphology, thermal and oxidative stabilities, water uptake and proton conductivity, and mechanical properties of CS/TCNT composite membranes were investigated. The CNTs coated with an insulated and hydrophilic titania layer eliminated the risk of electronic short‐circuiting. Moreover, the titania layer enhanced the interaction between TCNTs and chitosan to ensure the homogenous dispersion of TCNTs in the chitosan matrix. The water uptake of CS/TCNT composite membranes was reduced owing to the decrease of the effective number of the NH2 functional groups of chitosan. However, the CS/TCNT composite membranes exhibited better performance than a pure CS membrane in thermal and oxidative stability, proton conductivity, and mechanical properties. These results suggest that CS/TCNT composite membranes are promising materials for new proton‐exchange membranes. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43365.
Description of second flow field via the deformation of polystyrene phase in high‐density polyethylene matrix
Authors: Zhang Quan‐Ping , Xia Xiao-Chao , He Shan , Feng Jian-Min , Yang Ming‐Bo , Li Yin-Tao , Zhou Yuan-Lin
Published: January 2016

Real flow field has been critical in all kinds of injection molding, not only for understanding morphological evolution, but also for tailoring polymer physical property. Since the relaxation of PS phase in the HDPE matrix is successfully retarded by introduction of additional gas cooling, here, the second flow field in gas‐assisted injection molding is first calculated with the classical models for predicting the shapes of dispersed droplets in immiscible blend. The results indicate high gas penetration pressure facilitates strong second flow field. Gas penetration time is inversely proportional to the triggered flow intensity, which can be used for the qualitative comparison of the flow fields under various conditions. Importantly, the flow field can be designed by tailoring melt advancing rate, such as the penetration power and/or the penetration resistance of second fluid, which contributes to realizing the optimum coupling between external fields and chain architectures. Besides, this work opens a window for the understanding of real flow field under various processing conditions. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43374.
Influence of epichlorohydrin content on structure and properties of high‐ortho phenolic epoxy fibers
Authors: Jiao Mingli , Yang Kai , Cao Jian , Diao Quan , Zhang Wangxi , Yu Muhuo
Published: January 2016

The high‐ortho phenolic epoxy fibers (HPEFs) were prepared by the crosslinking of heat‐meltable spun filaments derived from melt‐spinning of the novolac epoxy resins copolymerized among phenol, formaldehyde, and epichlorohydrin (ECH) in the presence of zinc acetate and sulfuric acid catalyst, and cured in a combined solution of formaldehyde and hydrochloric acid. The resulting fibers were heat‐treated in N2 at elevated temperature. Infrared (IR) spectrometer, thermogravimetric analysis (TGA), scanning electron microscope (SEM), and electrical tensile strength apparatus were employed to characterize the change of functional groups, thermal performance, microstructure of fibers, and mechanical properties. The results show that the addition of ECH in the precursor resin can increase the content of long alkyl ether linkage, and gain the peak of thermal stability and mechanical strength. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43375.
Effective incorporation of TiO2 nanoparticles into polyamide thin‐film composite membranes
Authors: Kim Seong‐Joong , Lee Pyung‐Soo , Bano Saira , Park You‐In , Nam Seung‐Eun , Lee Kew‐Ho
Published: January 2016

The effectiveness of TiO2 nanoparticles in improving the performance of polyamide (PA) thin‐film composite (TFC) membranes has been investigated. PA TFC membranes were prepared by interfacial polymerization with m‐phenylenediamine (MPD) and 1,3,5‐benzene tricarbonyl trichloride (TMC) where TiO2 particles were added during and after interfacial polymerization. To distribute the TiO2 nanoparticles uniformly in the PA films, colloidally stable TiO2 sols were synthesized and added to the aqueous MPD solution rather than to an organic TMC solution. Through the use of different incorporation methods, TiO2 particles were located on the top surface, in PA film layer, and in both positions. In the case of dense PA layers, the hydrophilicity of the membranes was significantly improved due to the presence of TiO2 particles, resulting in an increased water flux. On the other hand, the enhancement of water flux was less significant when TiO2 particles were incorporated into a loose PA film that was prepared with additives. In addition, a BSA fouling test confirmed that TiO2 nanoparticles effectively improve the antifouling properties of the membranes for both dense and loose PA films. This effect is possibly due to increased hydrophilicity, covering of the fouling space, and a reduction in surface roughness. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43383.
Effect of different organic amino cations on SAPO‐34 for PES/SAPO‐34 mixed matrix membranes toward CO2/CH4 separation
Authors: Ahmad N. N. R. , Mukhtar H. , Mohshim D. F. , Nasir R. , Man Z.
Published: January 2016

Mixed matrix membranes (MMMs) embedded with functionalized SAPO‐34 were successfully synthesized and characterized. Two different types of organic amino cation, namely ethylenediamine (EDA) and hexylamine (HA), were used to functionalize SAPO‐34 particles prior to MMM synthesis. In this work, the effects of different functionalizing agents on the membrane morphology, pore size, and CO2/CH4 gas separation properties were investigated. Surface modification of SAPO‐34 was confirmed via X‐ray photoemission spectroscopy (XPS) where the presence of nitrogen atom was observed for the samples functionalized with amino cations. The dispersion of EDA‐functionalized SAPO‐34 particles was found to have better polymer/filler interface morphology as shown by field emission scanning electron microscopy (FESEM) analysis. The gas separation performance revealed that PES containing EDA‐functionalized SAPO‐34 exhibited better CO2/CH4 separation performance as compared to the MMMs containing HA‐functionalized SAPO‐34. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43387.