bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrowetting‐Induced Stiction Switch of a Microstructured Wire Surface for Unidirectional Droplet and Bubble Motion
Authors: Yan Yufeng , Guo Zhenyan , Zhang Xiaofang , He Linlin , Li Yan , Liu Kesong , Cai Jinhua , Tian Dongliang , Jiang Lei 
Published: May 2018

AbstractDirectional motion of fluid droplets is attracting considerable research attention. Despite much progress in this field, electrowetting‐based stiction switch that drives unidirectional transport of an underwater oil droplet or air bubble on a wire surface is still a challenge to realize. Here, a strategy to collect and unidirectionally transport an underwater oil droplet or air bubble on a porous polystyrene (PS) film‐coated copper wire surface through the combination of electrowetting‐induced stiction switch and buoyancy is demonstrated. The porous PS film‐coated copper wire fabricated by the breath figure method at a relative humidity of 75% can catch and hold an underwater oil droplet or air bubble without applied voltage. With increasing applied voltage, the stiction of the underwater oil droplet or air bubble on the porous PS film surface weakens because water increasingly wets the film surface. The underwater oil droplet or air bubble can move unidirectionally on the porous PS film‐coated wire surface upward or downward at a voltage larger than its critical voltage according to whether its density is lower or higher than that of water. This work should aid the development of devices displaying electrowetting‐based changes for use in fluid collection, manipulation, unidirectional transfer, release, and removal.
Shape Reconfiguration of a Biomimetic Elastic Membrane with a Switchable Janus Structure
Authors: Bai Jing , Shi Zixing , Yin Jie , Tian Ming , Qu Rongjun 
Published: May 2018

AbstractA method for the fabrication of a biomimetic Janus composite membrane is reported here. This approach is based on a membrane with a vertical gradient crosslinking degree, which is achieved through UV light–induced dimerization of anthracene grafted on poly(styrene‐block‐butadiene‐block‐styrene) chains in the presence of carbon nanotubes. UV light penetration is controlled by the accretion of carbon nanotubes to ultimately tailor the heterogeneous crosslinking degree in thickness. This kind of Janus structure is applied here for shape actuation. Here, solvent or shape memory effect–induced shape morphing is obtained via the heterogeneous swelling (deswelling) abilities of, or internal stress from, the Janus structure. By tailoring the UV light irradiation time, the irradiated region and the prestrain, sophisticated and multiple types of shape morphing are programed. In addition, this type of Janus structure can shift back to the homogeneous structure via dedimerization of the anthracene dimers upon thermal treatment, which provides extensive freedom for the design of smart responsive actuators.
A Subtractive Photoresist Platform for Micro‐ and Macroscopic 3D Printed Structures
Authors: Zieger Markus M. , Müller Patrick , Blasco Eva , Petit Charlotte , Hahn Vincent , Michalek Lukas , Mutlu Hatice , Wegener Martin , Barner‐Kowollik Christopher 
Published: May 2018

AbstractThe selective removal of structural elements plays a decisive role in 3D printing applications enabling complex geometries. To date, the fabrication of complex structures on the microscale is severely limited by multistep processes. Herein, a subtractive photoresist platform technology that is transferable from microscopic 3D printing via direct laser writing to macroscopic structures via stereolithography is reported. All resist components are readily accessible and exchangeable, offering fast adaptation of the resist's property profile. The micro‐ and macroprinted structures can be removed in a facile fashion, without affecting objects based on standard photoresists. The cleavage is analyzed by time‐lapse optical microscopy as well as via in‐depth spectroscopic assessment. The mechanical properties of the printed materials are investigated by nanoindentation. Critically, the power of the subtractive resist platform is demonstrated by constructing complex 3D objects with flying features on the microscale.
Systematic Power Factor Enhancement in n‐Type NiETT/PVDF Composite Films
Authors: Menon Akanksha K. , Wolfe Rylan M. W. , Marder Seth R. , Reynolds John R. , Yee Shannon K. 
Published: May 2018

AbstractNickel ethenetetrathiolate (NiETT) coordination polymers are shown to exhibit high thermoelectric performance as pressed pellets. Because the material is insoluble, films are formed by fabricating a composite of the material in an inert polymer matrix, a process that adversely impacts thermoelectric properties. To date, a reliable and reproducible synthesis has not been reported, which was the motivation for a systematic study of the substeps involved to understand the reaction mechanism. The results of these studies yield optimized reaction conditions for high performance n‐type films, which are derived from empirical studies and material characterization. Herein, a reaction procedure is presented that gives reproducible properties when preparing batches in the 0.5–15 g range. The identity of the counterion, nickel equivalency, and oxidation extent are investigated, which provide insight into the synthetic reaction mechanism and the ligand‐centered oxidation process in these polymers. Optimized materials based on Na[NiETT] exhibit one of the highest n‐type thermoelectric performance for solution‐processed films reported to date, with power factors of 23 µW (m K)−2 (due to conductivities approaching 50 S cm−1) while maintaining their stability in ambient conditions.
Ultrasensitive Room‐Temperature Terahertz Direct Detection Based on a Bismuth Selenide Topological Insulator
Authors: Tang Weiwei , Politano Antonio , Guo Cheng , Guo Wanlong , Liu Changlong , Wang Lin , Chen Xiaoshuang , Lu Wei 
Published: May 2018

AbstractDespite their huge application capabilities, millimeter‐ and terahertz‐wave photodetectors still face challenges in the detection scheme. Topological insulators (TIs) are predicted to be promising candidates for long‐wavelength photodetection, due to the presence of Dirac fermions in their topologically protected surface states. However, photodetection based on TIs is usually hindered by the large dark current, originating from the mixing of bulk states with topological surface states (TSSs) in most realistic samples of TIs. Here millimeter and terahertz detectors based on a subwavelength metal–TI–metal (MTM) heterostructure are demonstrated. The achieved photoresponse stems from the asymmetric scattering of TSS, driven by the localized surface plasmon‐induced terahertz field, which ultimately produces direct photocarriers beyond the interband limit. The device enables high responsivity in both the self‐powered and bias modes even at room temperature. The achieved responsivity is over 75 A/W, with response time shorter than 60 ms in the self‐powered mode. Remarkably, the responsivity increases by several orders of magnitude in the biased configuration, with the noise‐equivalent power (NEP) of 3.6 × 10−13 W Hz−1/2 and a detectivity of 2.17 × 1011 cm Hz−1/2 W−1 at room temperature. The detection performances open a way toward realistic exploitation of TIs for large‐area, real‐time imaging within long‐wavelength optoelectronics.
Engineering Solid Electrolyte Interphase for Pseudocapacitive Anatase TiO2 Anodes in Sodium‐Ion Batteries
Authors: Xu Zheng‐Long , Lim Kyungmi , Park Kyu‐Young , Yoon Gabin , Seong Won Mo , Kang Kisuk 
Published: May 2018

AbstractAnatase TiO2 is considered as one of the promising anodes for sodium‐ion batteries because of its large sodium storage capacities with potentially low cost. However, the precise reaction mechanisms and the interplay between surface properties and electrochemical performance are still not elucidated. Using multimethod analyses, it is herein demonstrated that the TiO2 electrode undergoes amorphization during the first sodiation and the amorphous phase exhibits pseudocapacitive sodium storage behaviors in subsequent cycles. It is also shown that the pseudocapacitive sodium storage performance is sensitive to the nature of solid electrolyte interphase (SEI) layers. For the first time, it is found that ether‐based electrolytes enable the formation of thin (≈2.5 nm) and robust SEI layers, in contrast to the thick (≈10 nm) and growing SEI from conventional carbonate‐based electrolytes. First principle calculations suggest that the higher lowest unoccupied molecular orbital energies of ether solvents/ion complexes are responsible for the difference. TiO2 electrodes in ether‐based electrolyte present an impressive capacity of 192 mAh g−1 at 0.1 A g−1 after 500 cycles, much higher than that in carbonate‐based electrolyte. This work offers the clarified picture of electrochemical sodiation mechanisms of anatase TiO2 and guides on strategies about interfacial control for high performance anodes.
C4photosynthesis and transition of Kranz anatomy in cotyledons and leaves ofTetraena simplex
Authors: Muhaidat Riyadh , McKown Athena D. , Al Zoubi Mazhar , Bani Domi Zakariya , Otoum Osama 
Published: May 2018

Premise of the StudyTetraena simplexis an independently evolved C4species in the Zygophylloideae (Zygophyllaceae) and a characteristic forb of saline flats in hot and sandy desert habitats. During early ontogeny, the species had a morphological shift from planar cotyledons (dorsiventral symmetry) to terete, succulent leaves (radial symmetry). We tested whether this shift had a corresponding change in internal Kranz anatomy and tissue patterning.MethodsFor a comprehensive characterization of C4photosynthesis across early ontogeny inT. simplex, structural and ultrastructural anatomical properties and localization patterns, activities, and immunoblotting of key C4photosynthetic enzymes were compared in mesophyll and bundle sheath tissues in cotyledons and leaves.Key ResultsCotyledons and leaves possessed different types of Kranz anatomy (atriplicoid type and a “Tetraena” variant of the kochioid type, respectively), reflecting the change in leaf morphology. In bundle sheath cells, key differences in ultrastructural features included increased organelle numbers and chloroplast thylakoid stacking. C4enzymes had strict tissue‐specific localization patterns within bundle sheath and mesophyll cells in both cotyledons and leaves. The decarboxylaseNAD‐MEmaintained the highest activity, increasing from cotyledons to leaves. This classifiedT.simplexas fully C4across ontogeny and a strictlyNAD‐MEbiochemical subtype.ConclusionsTetraena simplexcotyledons and leaves showed differences in Kranz type, with associated progression in ultrastructural features, and differing activities/expression levels of C4enzymes. Furthermore, leaves characterized a new “Tetraena” variation of the kochioid Kranz anatomy.
Lewis‐Base‐Catalyzed Domino Reaction of Morita–Baylis–Hillman Carbonates of Isatins with Enolizable Cyclic Carbonyl Compounds: Stereoselective Access to Spirooxindole‐Pyrans
Authors: Yadav Anubha , Banerjee Joyanta , Arupula Sanjeeva K. , Mobin Shaikh M. , Samanta Sampak 
Published: May 2018

AbstractThe present paper reports an efficient, organocatalytic, environmentally friendly and stereoselective [3+3] one‐pot allylic alkylation/oxa‐Michael reaction by involving a wide range of Morita–Baylis–Hillman (MBH) carbonates of isatins and several pharmacologically attractive enolizable C−H activated cyclic carbonyl compounds such as 1,3‐binucleophiles, namely pyrazolones, isoxazolones, 4‐hydroxyxoumarins, 4‐hydroxy‐6‐methyl‐α‐pyrone, lawsone and dimedone in a biomass‐derived 2‐MeTHF as green solvent catalyzed by DABCO as a solid Lewis‐base catalyst. This protocol delivers a unique class of medicinally promising spirooxindole‐fused‐dihydropyran scaffolds.
Chemo‐enzymatische Totalsynthese von Oxosorbicillinol, Sorrentanon, Rezishanon B und C, Sorbicatechol A, Bisvertinolon und (+)‐Epoxysorbicillinol
Authors: Sib Anna , Gulder Tobias A. M. 
Published: May 2018

AbstractDie Sorbicillinoide sind eine große Familie fungaler Naturstoffe, die häufig sehr anspruchsvolle Molekülarchitekturen aufweisen. Abhängig von ihrer individuellen Struktur zeigen sie starke biologische Aktivitäten, die von Radikalfänger‐ und anti‐infektiven Eigenschaften bis hin zu Cytotoxizität reichen können. Trotz ihres daraus resultierenden, großen biomedizinischen Potenzials und des allgemeinen Interesses an diesen faszinierenden Strukturen aus dem Feld der Naturstoff‐Totalsynthese sind viele Sorbicillinoide zurzeit nicht präparativ zugänglich, was ihre eingehende biologische Charakterisierung und strukturelle Diversifizierung verhindert. Durch die Nutzung der rekombinanten Oxidoreduktase SorbC und einfach präparativ zugänglicher Sorbicillin‐artiger Vorstufen wurden enantioselektive, chemo‐enzymatische Ein‐Topf‐Syntheserouten zu einem breiten Spektrum an Sorbicillinoiden entwickelt. Dadurch wurden Totalsynthesen von Oxosorbicillinol, Sorrentanon, Rezishanon B und C, Sorbicatechol A, Bisvertinolon und (+)‐Epoxysorbicillinol ermöglicht.
Self‐Reporting Inhibitors: A Single Crystallization Process To Obtain Two Optically Pure Enantiomers
Authors: Ye Xichong , Cui Jiaxi , Li Bowen , Li Na , Zhang Jie , Wan Xinhua 
Published: May 2018

AbstractCollection of two optically pure enantiomers in a single crystallization process can significantly increase the chiral separation efficiency but this is difficult to realize. Now a self‐reporting strategy is presented for visualizing the crystallization process by a dyed self‐assembled inhibitor made from the copolymers with tri(ethylene glycol)‐grafting polymethylsiloxane as the main chain and poly(N6‐methacryloyl‐l‐lysine) as side chains. When applied with seeds together for the fractional crystallization of conglomerates, the inhibitors can label the formation of the secondary crystals and guide the complete separation process of two enantiomers with colorless crystals as the first product and red crystals as the second. This method leads to high optical purity of d/l‐Asn⋅H2O (99.9 % ee for d‐crystals and 99.5 % for l‐crystals) in a single crystallization process. It requires a small amount of additives and shows excellent recyclability.
Isolierung schwer fassbarer Komplexe mit einer Aluminium‐Element‐Mehrfachbindung: Am Horizont zeichnet sich eine neue Aluminiumchemie ab
Authors: Bag Prasenjit , Weetman Catherine , Inoue Shigeyoshi 
Published: May 2018

AbstractDie Synthese und Isolierung von stabilen Hauptgruppenkomplexen mit Mehrfachbindungen ist seit mehreren Dekaden von größtem Interesse. Eine Vielfalt solcher Komplexe wurde durch den Einsatz von sterisch anspruchsvollen Substituenten erhalten, die sowohl kinetische als auch thermodynamische Stabilität verleihen. Die meisten dieser Verbindungen haben außergewöhnliche strukturelle und elektronische Eigenschaften, die das klassische Konzept der kovalenten Mehrfachbindung auf die Probe stellen. Trotz der hohen natürlichen Häufigkeit von Aluminium sind entsprechende Verbindungen für dieses Element besonders selten. Die Stammverbindung Al2H2 (Dialumen) wurde mittels theoretischer Methoden als extrem instabil charakterisiert, weshalb Mehrfachbindungen mit Aluminium ein präparativ anspruchsvolles Ziel sind. Dieser Aufsatz bietet eine Zusammenstellung der neuesten Syntheseansätze und der Möglichkeiten zur Gestaltung von Ligandensystemen für die Isolierung von Komplexen mit homo‐ und heteroatomaren Aluminium‐Mehrfachbindungen. Außerdem wird die Reaktivität dieser neuartigen Verbindungen ausführlich diskutiert.
Rapid Photoactuation of a DNA Nanostructure using an Internal Photocaged Trigger Strand
Authors: Liu Minghui , Jiang Shuoxing , Loza Omar , Fahmi Nour Eddine , Šulc Petr , Stephanopoulos Nicholas 
Published: May 2018

AbstractA reconfigurable DNA nano‐tweezer is reported that can be switched between a closed and open state with a brief pulse of UV light. In its initial state, the tweezer is held shut using a hairpin with a single‐stranded poly‐A loop. Also incorporated in the structure is a poly‐T trigger strand bearing seven photocaged residues. Upon illumination with 365 nm light, the cages are removed and the trigger strand hybridizes to the loop, opening the tweezer and increasing the distance between its arms from 4 to 18 nm. This intramolecular process is roughly 60 times faster than adding an external trigger strand, and provides a mechanism for the rapid interconversion of DNA nanostructures with light.
Amino Acid Assisted Incorporation of Dye Molecules within Calcite Crystals
Authors: Marzec Bartosz , Green David C. , Holden Mark A. , Coté Alexander S. , Ihli Johannes , Khalid Saba , Kulak Alexander , Walker Daniel , Tang Chiu , Duffy Dorothy M. , Kim Yi‐Yeoun , Meldrum Fiona C. 
Published: May 2018

AbstractBiomineralisation processes invariably occur in the presence of multiple organic additives, which act in combination to give exceptional control over structures and properties. However, few synthetic studies have investigated the cooperative effects of soluble additives. This work addresses this challenge and focuses on the combined effects of amino acids and coloured dye molecules. The experiments demonstrate that strongly coloured calcite crystals only form in the presence of Brilliant Blue R (BBR) and four of the seventeen soluble amino acids, as compared with almost colourless crystals using the dye alone. The active amino acids are identified as those which themselves effectively occlude in calcite, suggesting a mechanism where they can act as chaperones for individual molecules or even aggregates of dyes molecules. These results provide new insight into crystal–additive interactions and suggest a novel strategy for generating materials with target properties.
Structure and Biocatalytic Scope of Coclaurine N‐Methyltransferase
Authors: Bennett Matthew R. , Thompson Mark L. , Shepherd Sarah A. , Dunstan Mark S. , Herbert Abigail J. , Smith Duncan R. M. , Cronin Victoria A. , Menon Binuraj R. K. , Levy Colin , Micklefield Jason 
Published: May 2018

AbstractBenzylisoquinoline alkaloids (BIAs) are a structurally diverse family of plant secondary metabolites, which have been exploited to develop analgesics, antibiotics, antitumor agents, and other therapeutic agents. Biosynthesis of BIAs proceeds via a common pathway from tyrosine to (S)‐reticulene at which point the pathway diverges. Coclaurine N‐methyltransferase (CNMT) is a key enzyme in the pathway to (S)‐reticulene, installing the N‐methyl substituent that is essential for the bioactivity of many BIAs. In this paper, we describe the first crystal structure of CNMT which, along with mutagenesis studies, defines the enzymes active site architecture. The specificity of CNMT was also explored with a range of natural and synthetic substrates as well as co‐factor analogues. Knowledge from this study could be used to generate improved CNMT variants required to produce BIAs or synthetic derivatives.
Higher Acenes by On‐Surface Dehydrogenation: From Heptacene to Undecacene
Authors: Zuzak Rafal , Dorel Ruth , Kolmer Marek , Szymonski Marek , Godlewski Szymon , Echavarren Antonio M. 
Published: May 2018

AbstractA unified approach to the synthesis of the series of higher acenes up to previously unreported undecacene has been developed through the on‐surface dehydrogenation of partially saturated precursors. These molecules could be converted into the parent acenes by both atomic manipulation with the tip of a scanning tunneling and atomic force microscope (STM/AFM) as well as by on‐surface annealing. The structure of the generated acenes has been visualized by high‐resolution non‐contact AFM imaging and the evolution of the transport gap with the increase of the number of fused benzene rings has been determined on the basis of scanning tunneling spectroscopy (STS) measurements.
Access to the Enantiopure Axially Chiral Cyclophane Isoplagiochin D through Atropo‐diastereoselective Heck Coupling
Authors: Meidlinger Daniel , Marx Lisa , Bordeianu Catalina , Choppin Sabine , Colobert Françoise , Speicher Andreas 
Published: May 2018

AbstractMacrocyclization is typically the key step in the syntheses of cyclophane‐type natural products. Considering cyclophanes with axially chiral biaryl moieties, the control of atroposelectivity is essential with biological activity and is synthetically challenging. We report an atroposelective approach involving Heck cyclization, which for the first time enables the total synthesis of an enantiopure macrocyclic bis(bibenzyl), namely isoplagiochin D. An enantiopure sulfinyl auxiliary in the ortho position of a biaryl axis (still flexible) was used to induce an atropo‐diastereoselective Heck coupling (up to 98 % de). The traceless character of the sulfinyl auxiliary enables the introduction of a hydroxy group to give the target molecule with 98 % ee as well.
Experimental Realisation of Elusive Multiple‐Bonded Aluminium Compounds: A New Horizon in Aluminium Chemistry
Authors: Bag Prasenjit , Weetman Catherine , Inoue Shigeyoshi 
Published: May 2018

AbstractThe synthesis and isolation of stable main group compounds featuring multiple bonds has been of great interest for several decades. A plethora of such multiply bonded complexes have been obtained by using sterically demanding substituents that provide both kinetic and thermodynamic stability. Most of these compounds have unusual structural and electronic properties that challenge the classical concept of covalent multiple bonding. In contrast, analogous aluminium compounds are scarce in spite of its high natural abundance. The parent dialumene (Al2H2) has been calculated to be extremely unstable, thus making compounds containing Al multiple bonds a challenging synthetic target. This Review provides an overview of the recent advances in the cutting edge synthetic approaches and the careful ligand design used to obtain aluminium homo‐ and heterodiatomic multiply bonded complexes. In addition, the reactivity of these novel compounds towards various small molecules and reagents will be discussed herein.
Observation of a Metastable P‐Heterocyclic Radical by Muonium Addition to a 1,3‐Diphosphacyclobutane‐2,4‐diyl
Authors: Ito Shigekazu , Ueta Yasuhiro , Koshino Kota , Kojima Kenji M. , McKenzie Iain , Mikami Koichi 
Published: May 2018

AbstractA 1,3‐diphosphacyclobutane‐2,4‐diyl contains a unique unsaturated cyclic unit, and the presence of radical‐type centers have been expected as a source of functionality. This study demonstrates that the P‐heterocyclic singlet biradical captures muonium (Mu=[μ+e−]), the light isotope of a hydrogen radical, to generate an observable P‐heterocyclic paramagnetic species. Investigation of a powder sample of 2,4‐bis(2,4,6‐tri‐t‐butylphenyl)‐1‐t‐butyl‐3‐benzyl‐1,3‐diphosphacyclobutane‐2,4‐diyl using muon (avoided) level‐crossing resonance (μLCR) spectroscopy revealed that muonium adds to the cyclic P2C2 unit. The muon hyperfine coupling constant (Aμ) indicated that the phosphorus atom bearing the t‐butyl group trapped muonium to provide a metastable P‐heterocyclic radical involving the ylidic MuP(<)=C moiety. The observed regioselective muonium addition correlates the canonical formula of 1,3‐diphosphacyclobutane‐2,4‐diyl.