bluuebunny/crossref_metadata_2025_split huggingface dataset:
Light‐Activated Nanoprobes for Biosensing and Imaging
Authors: Li Mengyuan , Zhao Jian , Chu Hongqian , Mi Yongsheng , Zhou Zehao , Di Zhenghan , Zhao Meiping , Li Lele 
Published: October 2018

AbstractFluorescent nanoprobes are indispensable tools to monitor and analyze biological species and dynamic biochemical processes in cells and living bodies. Conventional nanoprobes have limitations in obtaining imaging signals with high precision and resolution because of the interference with biological autofluorescence, off‐target effects, and lack of spatiotemporal control. As a newly developed paradigm, light‐activated nanoprobes, whose imaging and sensing activity can be remotely regulated with light irradiation, show good potential to overcome these limitations. Herein, recent research progress on the design and construction of light‐activated nanoprobes to improve bioimaging and sensing performance in complex biological systems is introduced. First, recent innovative strategies and their underlying mechanisms for light‐controlled imaging are reviewed, including photoswitchable nanoprobes and phototargeted nanosystems. Subsequently, a short highlight is provided on the development of light‐activatable nanoprobes for biosensing, which offer possibilities for the remote control of biorecognition and sensing activity in a precise manner both temporally and spatially. Finally, perspectives and challenges in light‐activated nanoprobes are commented.
Distinctive Nanocrater Structures in Hybrid Electron‐Collecting Buffer Layers for High Efficiency Polymer:Nonfullerene Solar Cells
Authors: Seo Jooyeok , Lee Chulyeon , Kim Hwajeong , Kim Youngkyoo 
Published: October 2018

AbstractHere distinctive nanocrater structures generated in the low temperature‐processed hybrid electron‐collecting buffer layers (h‐ECBLs), consisting of zinc oxide (ZnO) and poly(2‐ethyl‐2‐oxazoline) (PEOz), for high efficiency inverted‐type polymer:nonfullerene solar cells are reported. The ZnO:PEOz h‐ECBLs are prepared from their precursor films via thermal annealing at 110–130 °C, which is far lower than conventional condition (200 °C). Results show that the power conversion efficiency (PCE) of solar cells is noticeably improved by introducing the h‐ECBLs with 6 wt% PEOz but turned down at higher PEOz contents irrespective of the annealing temperature (from 9.25% to 11.41% at 120 °C and from 10.19% to 12.03% at 130 °C). The improved PCE is explained by the increased electron mobility in the h‐ECBLs (6 wt%) due to the reduced oxygen deficiency of ZnO by the PEOz components as well as the generated nanocrater (wrinkled at 120 °C) structures leading to the enhanced interfacial area and contact with the active layers.
Hierarchical Macro–Mesoporous Polymeric Carbon Nitride Microspheres with Narrow Bandgap for Enhanced Photocatalytic Hydrogen Production
Authors: Si Yinsong , Huang Taoqing , Li Qiuju , Huang Yuting , Gao Shang‐Peng , Chen Min , Wu Limin 
Published: October 2018

AbstractPolymeric carbon nitride (PCN) is emerging as promising visible‐light photocatalyst but remains a challenge in greatly improving its photocatalytic activity. The superiority of multiscale porous nanostructures in mass transfer, active site exposure, solar energy harvesting, and rates of reactions are verified in achieving superior photocatalytic activity; however, hierarchical porous PCN microspheres with macropores and mesopores simultaneously are rarely reported in the literature to date. Herein hierarchical macroporous–mesoporous PCN microspheres (HM‐PCNs) are presented for highly enhanced photocatalytic hydrogen production via an in situ precursor transformation technique. Utilizing the solubility difference between cyanamide and dicyanadiamide in aqueous solution, the in situ transformation of PCN precursor from cyanamide to dicyandiamide along the wall surfaces of the hierarchical porous SiO2 microspheres can produce robust HM‐PCNs with both hierarchical macro–mesopores structure and narrow bandgap (1.88 eV). The obtained HM‐PCNs present enhanced light absorption, promoted charge separation and transfer, and thus demonstrate highly enhanced hydrogen evolution activity (4635.8 µmol h−1 g−1) by a factor of 31.7 over the pristine PCN. Ab initio calculations indicate that C atoms at the outmost positions of the pores greatly reduce the bandgap and facilitate the electron–hole separation.
Iridium‐Catalyzed Sequential sp3 C−H Alkylation of an N‐Methyl Group with Alkenes Towards the Synthesis of α‐Substituted Amines
Authors: Hattori Hiroshi , Nishimura Takahiro 
Published: October 2018

AbstractIridium‐catalyzed sequential sp3 C−H alkylation of an N‐methyl group proceeded to give α‐substituted amines, where, in addition to the achiral amines, chiral amines were prepared in one pot via sequential reactions with two different alkenes.magnified image
Liquid‐Like SiO2‐g‐PDMS Coatings on Wood Surfaces with Underwater Durability, Antifouling, Antismudge, and Self‐Healing Properties
Authors: Wang Yaru , Yan Wenqing , Frey Marion , Vidiella del Blanco Marta , Schubert Mark , Adobes‐Vidal Maria , Cabane Etienne 
Published: October 2018

AbstractRecent research on surfaces with special wettability has lead to the development of “liquid surfaces”, obtained through the immobilization of a lubricant liquid on a porous interface, or through the grafting of flexible polymer chains on smooth surfaces. The latter method to fabricate durable protective coatings on wood surfaces is adapted in the current work. The method is based on a first modification with a silicon oxide layer, followed by the grafting of polydimethylsiloxane (PDMS) chains. The obtained surfaces are hydrophobic, and are highly durable when compared to classical superhydrophobic coatings, in particular after prolonged immersion in water. A self‐healing ability, provided by the rearrangement of the PDMS chains after plasma treatment, is reported herein. Finally, the coatings have antismudge, antifouling, and antibacterial properties. With durable water repelling properties, quick self‐healing ability, antismudge, antifouling, and antibacterial properties, the durability of wood is increased. This research demonstrates the protection potential of liquid‐like polymer coatings on wood, a material that will play an essential role in the transition toward more sustainable societies.
Supramolecular Synthon Approach in Designing Molecular Gels for Advanced Therapeutics
Authors: Dastidar Parthasarathi , Roy Rajdip , Parveen Rumana , Sarkar Koushik 
Published: October 2018

AbstractLow‐molecular‐weight gelators (LMWGs) are an important class of soft materials that offer various potential applications including drug delivery. Structural diversities of the reported LMWGs and lack of molecular‐level understanding of the self‐assembly process of gelation make it difficult to design a gelator a priori. Most often gelators are discovered in a serendipitous manner and second‐generation gelators are designed by modifying known gelling scaffolds. Since gel network within which the solvent molecules are immobilized is often found to be crystalline, a supramolecular synthon approach in the context of crystal engineering is demonstrated to be quite effective in designing LMWGs for various applications including therapeutics. Self‐drug‐delivery systems, wherein the need for a delivery vehicle does not exist, are becoming an effective alternative to conventional drug delivery systems. In the form of a simple gel (for non‐invasive topical application) or injectable gel (for invasive subcutaneous applications), LMWGs derived from drugs provide an effective way to develop self‐drug‐delivery systems. This review article encompasses the early development of LMWG research, describes gradual transition from discovering just a gelator to a gelator having potential material applications including drug delivery, and highlights the merit of supramolecular synthon approach in designing LMWGs for self‐drug‐delivery applications.
Near‐Infrared Photoresponse of Waveguide‐Integrated Carbon Nanotube–Silicon Junctions
Authors: Riaz Adnan , Alam Asiful , Selvasundaram Pranauv Balaji , Dehm Simone , Hennrich Frank , Kappes Manfred M. , Krupke Ralph 
Published: October 2018

AbstractSingle‐wall carbon nanotubes (CNTs) have been recently integrated into optical waveguides and operated as on‐chip electro‐optical transducers and nonclassical light sources. Here, first steps are taken toward complementary, waveguide‐integrated optoelectrical transducers based on CNTs. Few‐chiral CNTs are deposited from solution onto silicon waveguide and silicon electrodes, to form waveguide‐integrated CNT–silicon junctions. The junctions are characterized by means of spatially and spectrally resolved photocurrent measurements. Photocurrent spectra show wavelength‐dependent photocurrent contribution from silicon and from CNTs, however with the opposite sign. This behavior is explained by the relative positions of the Si band edges and the molecular orbitals of the CNTs. In CNT/Si junctions, only small diameter (7, 5) and (7, 6) CNTs are photoactive and contribute to photocurrent. When these CNTs are excited, electrons are injected into the silicon giving rise to photocurrent, whereas photoexcited larger diameter CNTs such as (8, 6), (8, 7), and (9, 7) do not contribute because of the lowest unoccupied molecular orbital (LUMO) position being too low for exciton dissociation. On the other hand, excitation of silicon yields photocurrents flowing in the opposite direction due to contact to larger diameter CNTs having suitable highest occupied molecular orbital (HOMO)–LUMO positions. The findings are supported by photocurrent maps and reflectance measurements.
An Analysis of the Factors Determining the Efficiency of Photocurrent Generation in Polymer:Nonfullerene Acceptor Solar Cells
Authors: Cha Hyojung , Tan Ching‐Hong , Wu Jiaying , Dong Yifan , Zhang Weimin , Chen Hu , Rajaram Sridhar , Narayan K. S. , McCulloch Iain , Durrant James R. 
Published: October 2018

AbstractHerein, a meta‐analysis of the device performance and transient spectroscopic results are undertaken for various donor:acceptor blends, employing three different donor polymers and seven different acceptors including nonfullerene acceptors (NFAs). From this analysis, it is found that the primary determinant of device external quantum efficiency (EQE) is the energy offset driving interfacial charge separation, ΔECS. For devices employing the donor polymer PffBT4T blended with NFA and fullerene acceptors, an energy offset ΔECS = 0.30 eV is required to achieve near unity charge separation, which increases for blends with PBDTTT‐EFT and P3HT to 0.36 and ≈1.2 eV, respectively. For blends with PffBT4T and PBDTTT‐EFT, a 100 meV decrease in the LUMO of the acceptor is observed to result in an approximately twofold increase in EQE. Steady state and transient optical data determine that this energy offset requirement is not associated with the need to overcome the polymer exciton binding energy and thereby drive exciton separation, with all blends studied showing efficient exciton separation. Rather, the increase in EQE with larger energy offset is shown to result from suppression of geminate recombination losses. These results are discussed in terms of their implications for the design of donor/NFA interfaces in organic solar cells, and strategies to achieve further advances in device performance.
Characterization of the mating system of a native perennial tetraploid herb, Silene stellata
Authors: Zhou Juannan , Zimmer Elizabeth A. , Fenster Charles B. , Dudash Michele R. 
Published: October 2018

Premise of the StudyNursery pollination systems can range from obligate to facultative. In a system where generalists provide substantial pollination service, an important question is whether the cost of seed predation outweighs the benefit provided by the nursery pollinator to cause the plant to evolve toward more generalized pollination. Using a facultative system native to North America, we tested whether nursery pollinator vs. strictly mutualistic generalists affect mating‐system parameters of the host plant and explored the implications for long‐term coevolution.MethodsWe used paternity analyses with 11 microsatellite markers to characterize the mating system of Silene stellata when pollination service is primarily through the nursery pollinator Hadena ectypa and generalist moths.Key ResultsOur experimental population of S. stellata was predominantly outcrossing (average outcrossing rate t = 0.83), and mating‐system parameters were similar between pollinator groups. We detected significant correlations in both selfing and outcrossed paternity at the fruit and maternal family level, corresponding to limited pollen dispersal (mean = 3.9 m). Among individuals, variation in anther–stigma separation was positively associated with outcrossing rate, which suggests the importance of herkogamy in preventing selfing.ConclusionsCorrelated paternity suggests that seeds from the same fruit and/or plants are sired by a limited number of pollen donors, resulting from low pollen dispersal and potential male–male competition. The similar mating‐system parameters of the two pollinator groups suggest that selection for higher outcrossing in S. stellata is likely to be through floral design rather than through increased pollinator specialization with H. ectypa.
A Straightforward Synthesis of Polyfluorinated Furan Derivatives and Their Property
Authors: Agou Tomohiro , Nemoto Seiya , Yamada Shigeyuki , Konno Tsutomu , Mizuhata Yoshiyuki , Tokitoh Norihiro , Ebina Ryota , Ishii Akihiko , Hosoya Takaaki , Fukumoto Hiroki , Kubota Toshio 
Published: October 2018

AbstractAn abbreviated synthesis of hexafluorocyclopentane‐annulated 2,5‐diarylfurans has been developed. 1,2‐Dichloro‐3,3,4,4,5,5‐hexafluorocyclopentene was converted to corresponding polyfluorinated 1,2‐diaroylalkenes, treatment of which with P(OEt)3 afforded the polyfluorinated 2,5‐diarylfurans. Solid‐state photo‐luminescence of the furan derivatives exhibited remarkable red‐shifts compared to fluorescence emissions in solution, probably because of intermolecular interactions in the solid state. Comparisons of the optical and electrochemical data of the fluorinated furan derivatives with those of a non‐fluorinated 2,5‐diarylfuran suggest that the perfluorocycloalkane‐annulation effectively enhances the electron‐accepting ability of the 2,5‐diarylfuran framework.
Light/Copper Relay for Aerobic Fragmentation of Lignin Model Compounds
Authors: Zhou Wang , Nakahashi Junki , Miura Tomoya , Murakami Masahiro 
Published: October 2018

AbstractLignin model compounds undergo aerobic oxidation upon relay action of light and copper to afford isolable fragments. Considerably better efficiency and different product distribution are achieved in comparison to thermal copper‐catalyzed aerobic fragmentation.
N6‐Methyladenosine‐Sensitive RNA‐Cleaving Deoxyribozymes
Authors: Sednev Maksim V. , Mykhailiuk Volodymyr , Choudhury Priyanka , Halang Julia , Sloan Katherine E. , Bohnsack Markus T. , Höbartner Claudia 
Published: October 2018

AbstractDeoxyribozymes are synthetic enzymes made of DNA that can catalyze the cleavage or formation of phosphodiester bonds and are useful tools for RNA biochemistry. Herein, we report new RNA‐cleaving deoxyribozymes to interrogate the methylation status of target RNAs, thereby providing an alternative method for the biochemical validation of RNA methylation sites containing N6‐methyladenosine, which is the most wide‐spread and extensively investigated natural RNA modification. The developed deoxyribozymes are sensitive to the presence of N6‐methyladenosine in RNA near the cleavage site. One class of these DNA enzymes shows faster cleavage of methylated RNA, while others are strongly inhibited by the modified nucleotide. The general applicability of the new deoxyribozymes is demonstrated for several examples of natural RNA sequences, including a lncRNA and a set of C/D box snoRNAs, which have been suggested to contain m6A as a regulatory element that influences RNA folding and protein binding.
Konstruktion linearer und verzweigter Tetraborane durch 1,1‐ und 1,2‐Diborierung von Diborenen
Authors: Stennett Tom E. , Bertermann Rüdiger , Braunschweig Holger 
Published: October 2018

AbstractSterisch ungehinderte Diborene mit einer Benzylphosphan‐Chelatgruppe gehen mit Bis(catechol)diboran in Abwesenheit eines Katalysators Diborierungsreaktionen ein. Bei den untersuchten symmetrischen Diborenen finden 1,2‐Diborierungen statt, wohingegen ein unsymmetrisches Derivat durch eine formale 1,1‐Diborierung zu einem Triborylboran‐Phosphan‐Addukt führt. Ein verwandtes Borylborylen lieferte ebenfalls durch 1,2‐Diborierung ein Borylen‐Boran‐Addukt.
Metall‐Phosphor‐Trichalkogenide (MPCh3): von der Synthese zu aktuellen Energieanwendungen
Authors: Gusmão Rui , Sofer Zdenek , Pumera Martin 
Published: October 2018

AbstractAufgrund ihrer speziellen physikalischen und chemischen Eigenschaften stehen zweidimensionale (2D‐)Schichtmaterialien im Fokus der aktuellen materialwissenschaftlichen Forschung. Dies schließt Schichten ein, die aus einem einzelnen Element (Graphen, Phosphoren), zwei Elementen (Metall‐Dichalkogenide) oder mehreren Elementen bestehen. Die erstmals im späten 19. Jahrhundert synthetisierten Metall‐Phosphor‐Trichalkogenide (MPCh3 mit Ch=S, Se) bilden eine besondere Klasse von 2D‐Schichtmaterialien. MPCh3‐Verbindungen, die in den 1970er Jahren wegen ihres ungewöhnlichen Interkalationsverhaltens in Bezug auf ihre magnetischen Eigenschaften sowie als Sekundärelektroden in Lithium‐Batterien untersucht worden waren, wurden erst vor kurzem als 2D‐Nanomaterialien wiederentdeckt. Zahlreiche aktuelle Berichte über MPCh3 für die Wasserspaltungskatalyse und Energiespeicherung werden umfassend erörtert, wobei der Fokus auf der Synthese dieser Materialien und ihren wesentlichsten Eigenschaften liegt. Dieser Kurzaufsatz soll als Ausgangsbasis für die Erkundung solcher 2D‐Schichtmaterialien für elektrochemische Energieanwendungen dienen.
Palladium‐Catalyzed Enantioselective Addition of Chiral Metal Enolates to In Situ Generated ortho‐Quinone Methides
Authors: Göricke Fabian , Schneider Christoph 
Published: October 2018

AbstractWe describe herein a conceptually novel, cooperative Brønsted acid/base catalyzed process for the conjugate addition of cyclic β‐keto esters to ortho‐quinone methides both generated in situ. Upon hemiacetalization, densely functionalized chiral chromans with two adjacent quaternary and additionally a tertiary stereogenic center were obtained with very good diastereoselectivity (up to >95:5 d.r.) and typically excellent enantioselectivity (up to >99 % ee). The striking feature and key to success is the dual catalytic activation of both nucleophile and electrophile in two separate cycles with a single chiral catalyst.
Mannich‐type Reactions of Cyclic Nitrones: Effective Methods for the Enantioselective Synthesis of Piperidine‐containing Alkaloids
Authors: Lisnyak Vladislav G. , Lynch‐Colameta Tessa , Snyder Scott A. 
Published: October 2018

AbstractEven though there are dozens of biologically active 2‐substituted and 2,6‐disubstituted piperidines, only a limited number of approaches exist for their synthesis. Herein is described two Mannich‐type additions to nitrones, one using β‐ketoacids under catalyst‐free conditions and another using methyl ketones in the presence of chiral thioureas, which can generate a broad array of such 2‐substituted materials, as well as other ring variants, in the form of β‐N‐hydroxy‐aminoketones. Both processes have broad scope, with the latter providing products with high enantioselectivity (up to 98 %). The combination of these methods, along with other critical steps, has enabled 8‐step total syntheses of the 2,6‐disubstituted piperidine alkaloids (−)‐lobeline and (−)‐sedinone.
Construction of Linear and Branched Tetraboranes by 1,1‐ and 1,2‐Diboration of Diborenes
Authors: Stennett Tom E. , Bertermann Rüdiger , Braunschweig Holger 
Published: October 2018

AbstractSterically unencumbered diborenes based on a benzylphosphine chelate undergo diboration reactions with bis(catecholato)diboron in the absence of a catalyst to yield tetraboranes. The symmetrical diborenes studied undergo 1,2‐diborations, whereas an unsymmetrical derivative was found to yield a triborylborane–phosphine adduct as the result of a formal 1,1‐diboration. A related borylborylene compound also underwent a 1,2‐diboration to produce a borylene–borane adduct.
Metal Phosphorous Trichalcogenides (MPCh3): From Synthesis to Contemporary Energy Challenges
Authors: Gusmão Rui , Sofer Zdenek , Pumera Martin 
Published: October 2018

AbstractOwing to their unique physical and chemical properties, layered two‐dimensional (2D) materials have been established as the most significant topic in materials science for the current decade. This includes layers comprising mono‐element (graphene, phosphorene), di‐element (metal dichalcogenides), and even multi‐element. A distinctive class of 2D layered materials is the metal phosphorous trichalcogenides (MPCh3, Ch=S, Se), first synthesized in the late 1800s. Having an unusual intercalation behavior, MPCh3 were intensively studied in the 1970s for their magnetic properties and as secondary electrodes in lithium batteries, but fell from scrutiny until very recently, being 2D nanomaterials. Based on their synthesis and most significant properties, the present surge of reports related to water‐splitting catalysis and energy storage are discussed in detail. This Minireview is intended as a baseline for the anticipated new wave of researchers who aim to explore these 2D layered materials for their electrochemical energy applications.
Concise synthesis and antibacterial evaluation of novel 3‐(1,4‐disubstituted‐1,2,3‐triazolyl)uridine nucleosides
Authors: Tachallait Hamza , Bouyahya Abdelhakim , Talha Aicha , Bakri Youssef , Dakka Nadia , Demange Luc , Benhida Rachid , Bougrin Khalid 
Published: October 2018

AbstractWe report herein a simple and efficient synthesis of a new series of antibacterial uridine nucleosides. The strategy involved a sequential silylation/N‐glycosylation/N‐propargylation procedure of uracil 1 for preparing the dipolarophile 5 in good yield. A series of novel uridine‐[1,2,3]triazole nucleosides 6a–j were efficiently synthesized via the copper‐catalyzed azide–alkyne cycloaddition (CuAAC) from dipolarophile 5 with different selected azides. The reactions were carried out under both conventional and ultrasonic irradiation conditions. In general, improvements were observed when reactions were carried out under sonication. Their antibacterial potential has been evaluated by means of a micro‐dilution assay against either Gram‐positive or Gram‐negative bacteria. Compounds 6i and 6j have shown significant bactericidal activity against Staphylococcus aureus (MIC = 10 and 6 μM, respectively), and 6h against Escherichia coli (MIC = 8 μM). Moreover, antibacterial kinetic assays showed that 6i and 6j significantly reduced the S. aureus growth rate at the MIC concentration, after 6 h, compared to their deprotected analogs, 6k and 6l, respectively. Compound 6h also significantly reduced the growth of E. coli. These antibacterial effects may be related to the penetrating properties of these compounds, as revealed by the leakage of nucleic acids from the sensitive strains.