bluuebunny/crossref_metadata_2025 huggingface dataset:
Polarised Moonlight Guides Nocturnal Bull Ants Home
Authors: Freas Cody A , Narendra Ajay , Murray Trevor , Cheng Ken
Published: November 2024

For the first time in any animal, we show that nocturnal bull ants use the exceedingly dim polarisation pattern produced by the moon for overnight navigation. The sun or moon can provide directional information via their position; however, they can often be obstructed by clouds, canopy or the horizon. Despite being hidden, these bodies can still provide compass information through the polarised light pattern they produce/reflect. Sunlight produces polarised light patterns across the overhead sky as it enters the atmosphere, and solar polarised light is a well-known compass cue for navigating animals. Moonlight produces an analogous pattern, albeit a million times dimmer than sunlight. Here we show evidence that polarised moonlight forms part of the celestial compass of navigating nocturnal ants. Nocturnal bull ants leave their nest at twilight and rely heavily on the overhead solar polarisation pattern to navigate. Yet many foragers return home overnight when the sun cannot guide them. We demonstrate that these bull ants use polarised moonlight to navigate home during the night, by rotating the overhead polarisation pattern above homing ants, who alter their headings in response. Furthermore, these ants can detect this cue throughout the lunar month, even under crescent moons, when polarised light levels are at their lowest. Finally, we show long-term incorporation of this moonlight pattern into the ants’ path integration system throughout the night for homing, as polarised sunlight is incorporated throughout the day.
Astrocytes mediate two forms of spike timing-dependent depression at entorhinal cortex-hippocampal synapses
Authors: Martínez-Gallego Irene , Coatl-Cuaya Heriberto , Rodriguez-Moreno Antonio
Published: November 2024

The entorhinal cortex (EC) connects to the hippocampus sending different information from cortical areas that is first processed at the dentate gyrus (DG) including spatial, limbic and sensory information. Excitatory afferents from lateral (LPP) and medial (MPP) perforant pathways of the EC connecting to granule cells of the DG play a role in memory encoding and information processing and are deeply affected in humans suffering Alzheimer’s disease and temporal lobe epilepsy, contributing to the dysfunctions found in these pathologies. The plasticity of these synapses is not well known yet, as are not known the forms of long-term depression (LTD) existing at those connections. We investigated whether spike timing-dependent long-term depression (t-LTD) exists at these two different EC-DG synaptic connections in mice, and whether they have different action mechanisms. We have found two different forms of t-LTD, at LPP- and MPP-GC synapses and characterised their cellular and intracellular mechanistic requirements. We found that both forms of t-LTD are expressed presynaptically and that whereas t-LTD at LPP-GC synapses does not require NMDAR, t-LTD at MPP-GC synapses requires ionotropic NMDAR containing GluN2A subunits. The two forms of t-LTD require different group I mGluR, mGluR5 LPP-GC synapses and mGluR1 MPP-GC synapses. In addition, both forms of t-LTD require postsynaptic calcium, eCB synthesis, CB1R, astrocyte activity, and glutamate released by astrocytes. Thus, we discovered two novel forms of t-LTD that require astrocytes at EC-GC synapses.
La sexualización del amor cristiano en el falso misticismo: huellas históricas, ambigüedad discursiva y semejanzas ideológicas
Authors: Marín-Mena Tomás J.
Published: November 2024

Este trabajo profundiza en la legitimación teológica perversa que el falso místico hace de sus actos sexuales. Con tal propósito, se hace una introducción histórica a las prácticas sexuales de carácter gnóstico y se considera el juego discursivo ambiguo entre lo exotérico y esotérico. Como ejemplo, se analizan algunas ambigüedades textuales en la obra de Javier Garrido OFM (condenado canónicamente por “falso misticismo”), a la luz de la investigación sobre los abusos sexuales de los hermanos Philippe OP y Jean Vanier. Asimismo, se exploran tres coincidencias con ideas ajenas al cristianismo que divinizan la pulsión sexual. Y se concluye apelando al discernimiento y la prudencia sobre el lenguaje místico-esponsal, y a la claridad en la moral sexual.
Caracterização de segmentos e atrativos turísticos por meio da mineração de dados e análise de redes no TripAdvisor
Authors: Perinotto André Riani Costa , Borges Júnia Lúcio de Castro , Braga Solano de Souza , Cembranel Priscila
Published: November 2024

Este estudo tem como objetivo compreender segmentos e atrativos turísticos por meio de uma metodologia replicável para outros estados brasileiros, ampliando a compreensão da percepção dos visitantes e facilitando a tomada de decisões por planejadores e gestores de destinos turísticos, assim como dando suporte a elaboração de políticas públicas para o setor. A metodologia se desenvolve por meio da aplicação de técnicas de mineração de dados textuais, análise textual estatística e análise de redes em um banco de dados qualitativo de avaliação dos visitantes deixados no TripAdvisor. São utilizadas informações resultantes de comentários provenientes de mídia social especializada em turismo com vistas a analisar o discurso dos visitantes sobre os atrativos turísticos do Piauí. Estes foram alcançados a partir do uso de Big Data aplicado aos rastros deixados pelos viajantes no TripAdvisor, a respeito dos atrativos turísticos. O banco de dados qualitativos foi tratado com o uso de softwares livres voltados à análise textual, tratamento dos dados e análise das redes. Conclui-se que, a partir dos resultados é possível compreender a demanda turística no Piauí e propor uma metodologia de análise do discurso associada à análise espacial capaz de fundamentar a gestão de destinos, atrativos e o desenvolvimento de políticas públicas.
SOX‐11 regulates LINE‐1 retrotransposon activity during neuronal differentiation
Authors: Orqueda Andrés J. , Gatti Cintia R. , Ogara María F. , Falzone Tomás L.
Published: October 2018

Activity of the human long interspersed nuclear elements‐1 (LINE‐1) retrotransposon occurs mainly in early embryonic development and during hippocampal neurogenesis. SOX‐11, a transcription factor relevant to neuronal development, has unknown functions in the control of LINE‐1 retrotransposon activity during neuronal differentiation. To study the dependence of LINE‐1 activity on SOX‐11 during neuronal differentiation, we induced differentiation of human SH‐SY5Y neuroblastoma cells and adult adipose mesenchymal stem cells (hASCs) to a neuronal fate and found increased LINE‐1 activity. We also show that SOX‐11 protein binding to the LINE‐1 promoter is higher in differentiating neuroblastoma cells, while knock‐down of SOX‐11 inhibits the induction of LINE‐1 transcription in differentiating conditions. These results suggest that activation of LINE‐1 retrotransposition during neuronal differentiation is mediated by SOX‐11.
New Core Technology for Light Metal Casting
Authors: Weise Jörg , Hilbers Jennifer , Handels Farina , Lehmhus Dirk , Busse Matthias , Heuser Michael
Published: October 2018

A new concept for lost cores for gravity castings is presented. In contrast to the conventional principle of thermally breaking down binder strength, demolding of the new cores is based on a mechanical collapse of parts of the filler material. For this purpose, the usual sand filler is substituted for hollow microspheres with defined isostatic compression strength. After casting, the core is subjected to high hydrostatic pressure, leading to destruction of the hollow filler and a resulting loss of core structural strength and volume, allowing it to be washed out easily. In the present study, phosphate‐, gypsum‐, and cement‐bonded cores with additions of hollow glass microspheres and cenospheres are produced and their bending strength and surface quality are determined. The core behavior during the casting process is evaluated using permanent mold gravity and low pressure aluminum casting experiments. Phosphate bonded materials containing 62 vol% of glass microspheres exhibit the best combination of surface quality and collapse behavior while reaching strength levels comparable to conventional sand cores. The study contributes to a deeper understanding of the collapse mechanisms, suggesting a major role of 1) open porosity of the matrix phase, 2) sufficient strength of the filler‐matrix interface, and 3) filler particle shell integrity. Due to a lack of the latter, cenospheres are proved unsuitable for the new demolding approach.
Stable Sulfur‐Intercalated 1T′ MoS2 on Graphitic Nanoribbons as Hydrogen Evolution Electrocatalyst
Authors: Ekspong Joakim , Sandström Robin , Rajukumar Lakshmy Pulickal , Terrones Mauricio , Wågberg Thomas , Gracia‐Espino Eduardo
Published: October 2018

The metastable 1T′ polymorph of molybdenum disulfide (MoS2) has shown excellent catalytic activity toward the hydrogen evolution reaction (HER) in water‐splitting applications. Its basal plane exhibits high catalytic activity comparable to the edges in 2H MoS2 and noble metal platinum. However, the production and application of this polymorph are limited by its lower energetic stability compared to the semiconducting 2H MoS2 phase. Here, the production of stable intercalated 1T′ MoS2 nanosheets attached on graphitic nanoribbons is reported. The intercalated 1T′ MoS2 exhibits a stoichiometric S:Mo ratio of 2.3 (±0.1):1 with an expanded interlayer distance of 10 Å caused by a sulfur‐rich intercalation agent and is stable at room temperature for several months even after drying. The composition, structure, and catalytic activity toward HER are investigated both experimentally and theoretically. It is concluded that the 1T′ MoS2 phase is stabilized by the intercalated agents, which further improves the basal planes′ catalytic activity toward HER.
Donor Conjugated Polymers with Polar Side Chain Groups: The Role of Dielectric Constant and Energetic Disorder on Photovoltaic Performance
Authors: Xu Bing , Yi Xueping , Huang Tzu‐Yen , Zheng Zilong , Zhang Junxiang , Salehi Amin , Coropceanu Veaceslav , Ho Carr Hoi Yi , Marder Seth R. , Toney Michael F. , Brédas Jean‐Luc , So Franky , Reynolds John R.
Published: October 2018

To better understand the correlation of the dielectric properties with the photovoltaic response in conjugated polymer:fullerene bulk heterojunction materials, the concept of introducing minimal structural change is employed to increase the polymer dielectric constant via polar cyano groups added to the end of butyl or octyl side chains in the poly(dithienosilole‐thienopyrrolodione) system. Density functional theory calculations confirm that the polar groups do not affect the polymer electronic structure but can lead to an increase in overall dipole moment depending on the polymer chain conformation. Despite the increased dielectric constant (from 2.7 to 4.3 for cyano‐octyl side chains and from 2.7 to 3.2 for the cyano‐butyl analogues), the device characteristics employing the cyano‐containing polymers are inferior to those of the devices made with unfunctionalized alkyl chains. It is found that the hole mobilities for the cyano‐containing polymers are two orders of magnitude lower compared to those for the parent polymers and suggest this is due to an increase in energetic disorder caused by the strong local permanent dipoles associated with the cyano groups. The study highlights the complexity in the relationship between the dielectric constant of organic materials, the morphologies that are induced, and their photovoltaic performance.
Thickness‐Dependent Facet Junction Control of Layered BiOIO3 Single Crystals for Highly Efficient CO2 Photoreduction
Authors: Chen Fang , Huang Hongwei , Ye Liqun , Zhang Tierui , Zhang Yihe , Han Xiaopeng , Ma Tianyi
Published: October 2018

Thin layer fabrication and crystal facet engineering favor the prompt charge transfer from bulk to the surface of a material and spatial charge separation among different facets, tremendously benefitting photocatalytic activity. However, the thickness and surface facet composition are considered as two entwined characteristics of layered materials with well‐defined and tunable shapes, which possess great promise to achieve the simultaneous manipulation of charge transfer and spatial separation. Herein, it is demonstrated that one solution for the aforementioned issue by controllably regulating the surface {010}/{100} facet junctions of a layered thickness‐tunable bismuth‐based material, BiOIO3. The attenuation in thickness of BiOIO3 nanoplates shortens the diffusion pathway of charge carriers, and more importantly the tuning of nanolayer thickness renders the ratio variation of the top {010} facet to the lateral {100} facet, which dominates the spatial separation of photogenerated electrons and holes. As a result, the highest CO evolution rate from CO2 reduction over BiOIO3 nanoplates with the optimal thickness and ratio of exposed facets reaches 5.42 µmol g−1 h−1, over 300% that of the bulk counterpart (1.77 µmol g−1 h−1). This work paves a new way for governing charge movement behaviors on the basis of the synergistic engineering of layer structure and exposing facets.
Thin‐Film Electrode Design for High Volumetric Electrochemical Performance Using Metal Sputtering‐Combined Ligand Exchange Layer‐by‐Layer Assembly
Authors: Ko Yongmin , Kwon Minseong , Song Yongkwon , Lee Seung Woo , Cho Jinhan
Published: October 2018

The design of electrode with high volumetric performance in energy storages still remains as a significant challenge because it simultaneously requires a high packing density of active materials for high energy density and a conductive porous structure for facile charge transfer. Here, a novel assembly process is introduced for thin‐film anodes for Li‐ion battery with a high volumetric energy density and rate performance by systematically controlling the interfacial structure between metal‐oxide nanoparticles and/or metal clusters. For this study, oleic‐acid‐stabilized Fe3O4 nanoparticles are layer‐by‐layer assembled with small organic molecules through a ligand exchange reaction, which enable a high packing density. During layer‐by‐layer deposition, periodic Pt‐sputtering onto multilayers significantly reduces the internal resistance of the electrodes but maintains the nanopores formed among the nanoparticles. The resulting anode exhibits an extremely high volumetric capacity of ≈3195 mA h cm−3 and rate performance, which are far superior to that reported for Li‐ion battery anodes. Additionally, all components in the electrodes have a stable covalent bond network between the metal atom and the amine group of organic molecule linker, allowing good cycle retention. This approach can be widely applied to the fabrication of various nanoparticle‐based electrodes, enabling maximum charge storage performance in confined volumes.
Decoupling Ionic and Electronic Currents in Melanin
Authors: Sheliakina Margarita , Mostert Albertus Bernardus , Meredith Paul
Published: October 2018

Melanin, the human skin pigment, has emerged as a model material for bioelectronic interfaces due to its biocompatibility, ability to be processed into electronic‐device‐grade thin films, and transducing charge transport properties. These charge transport properties have been suggested to be of a mixed protonic/electronic nature, regulated by a redox reaction that can be manipulated by changing the material's hydration state. However, to date, there are no detailed reports which clarify, quantify, or disentangle the protonic and electronic contributions to long‐range current conduction in melanin. Described herein, is a systematic hydration controlled electrical study on synthetic melanin thin films utilizing impedance/dielectric spectroscopy, which rationally investigates the protonic and electronic contributions. Through modeling and inspecting the frequency dependent behavior, it is shown that the hydration dependent charge transport is due to proton currents. Results show a real dielectric constant for hydrated melanin of order ≈1 × 103. Surprisingly, this very high value is maintained over a wide frequency range of ≈20–104 Hz. The electronic component appears to have little influence on melanin's hydration dependent conductivity: thus the material should be considered a protonic conductor, and not as previously suggested, a mixed protonic/electronic hybrid.
Preservation of Blood Vessels with an Oxygen Generating Composite
Authors: Zhang Huaifa , Dalisson Benjamin , Tran Simon , Barralet Jake
Published: October 2018

Damage caused by oxygen deficiency (hypoxia) is one of the major factors limiting tissue and organ preservation time. Cooling tissues slows down metabolic rate of cells thereby prolonging tissue and organ survival sufficiently to allow transport and transplantation within a few hours. Although metabolism is slowed, cells and some enzymes continue to consume oxygen that can render cold stored tissues hypoxic. Here, an oxygen‐generating composite (OGC) with sustained oxygen release is reported for ex vivo blood vessel preservation. Aorta segments are cultured under hypothermia for 25 days in vascular preservation media. The presence of OGC increases cell viability from 9 ± 6% to 96 ± 3% and retains 65 ± 8% of original KCl stimulated contractile force after 25 days compared with 25 ± 4% in controls. Culture for 7 days in nitrogen demonstrates proof‐of‐concept for normothermic blood vessel preservation, OGC increases the cell viability from 45 ± 15% to 78 ± 2%, and KCl stimulates contractile force from 49 ± 7% to 95 ± 8%, respectively. Oxygen release materials then may have a role in augmenting current preservation techniques.
Hollow Micro/Nanostructured Ceria‐Based Materials: Synthetic Strategies and Versatile Applications
Authors: Wang Zumin , Yu Ranbo
Published: October 2018

Hollow micro/nanostructured CeO2‐based materials (HMNCMs) have triggered intensive attention as a result of their unique structural traits, which arise from their hollowness and the fascinating physicochemical properties of CeO2. This attention has led to widespread applications with improved performance. Herein, a comprehensive overview of methodologies applied for the synthesis of various hollow structures, such as hollow spheres, nanotubes, nanoboxes, and multishelled hollow spheres, is provided. The synthetic strategies toward CeO2 hollow structures are classified into three major categories: 1) well‐established template‐assisted (hard‐, soft‐, and in situ template) methods; 2) newly emerging self‐template approaches, including selective etching, Ostwald ripening, the Kirkendall effect, galvanic replacement, etc.; 3) bottom‐up self‐organized formation synthesis (namely, oriented attachment and self‐deformation). Their underlying mechanisms are concisely described and discussed in detail, the differences and similarities of which are compared transversely and longitudinally. Niche applications of HMNCMs in a wide range of fields including catalysis, energy conversion and storage, sensors, absorbents, photoluminescence, and biomedicines are reviewed. Finally, an outlook of future opportunities and challenges in the synthesis and application of CeO2‐based hollow structures is also presented.
Nanoparticle‐Conjugate TLR7/8 Agonist Localized Immunotherapy Provokes Safe Antitumoral Responses
Authors: Nuhn Lutz , De Koker Stefaan , Van Lint Sandra , Zhong Zifu , Catani João Portela , Combes Francis , Deswarte Kim , Li Yupeng , Lambrecht Bart N. , Lienenklaus Stefan , Sanders Niek N. , David Sunil A. , Tavernier Jan , De Geest Bruno G.
Published: October 2018

Localized therapeutic modalities that subvert the tumor microenvironment from immune‐suppressive to pro‐immunogenic can elicit systemic antitumor immune responses that induce regression of directly treated as well as nontreated distal tumors. A key toward generating robust antitumor T cell responses is the activation of dendritic cells (DCs) in the tumor microenvironment. Treatment with agonists triggering various pattern recognition receptors is very efficient to activate DCs, yet suffers from the induction of serious immune‐related adverse effects, which is closely linked to their unfavorable PK/PD profile causing systemic immune activation and cytokine release. Here, it is reported that nanoparticle conjugation of a highly potent TLR7/8 agonist restricts immune activation to the tumor bed and its sentinel lymph nodes without hampering therapeutic antitumor efficacy. On a mechanistic level, it is confirmed that localized treatment with a nanoparticle‐conjugated TLR7/8 agonist leads to potent activation of DCs in the sentinel lymph nodes and promotes proliferation of tumor antigen‐specific CD8 T cells. Furthermore, therapeutic improvement upon combination with anti‐PDL1 checkpoint inhibition and Flt3L, a growth factor that expands and mobilizes DCs from the bone marrow, is demonstrated. The findings provide a rational base for localized tumor engineering by nanomedicine strategies that provide spatial control over immune‐activation.
Molybdenum Carbide Nanodots Enable Efficient Electrocatalytic Nitrogen Fixation under Ambient Conditions
Authors: Cheng Hui , Ding Liang‐Xin , Chen Gao‐Feng , Zhang Lili , Xue Jian , Wang Haihui
Published: October 2018

Electrocatalytic nitrogen fixation is considered a promising approach to achieve NH3 production. However, due to the chemical inertness of nitrogen, it is necessary to develop efficient catalysts to facilitate the process of nitrogen reduction. Here, molybdenum carbide nanodots embedded in ultrathin carbon nanosheets (Mo2C/C) are developed to serve as a catalyst candidate for highly efficient and robust N2 fixation through an electrocatalytic nitrogen reduction reaction (NRR). The as‐synthesized Mo2C/C nanosheets show excellent catalytic performance with a high NH3 yield rate (11.3 µg h−1 mg−1
Mo2C) and Faradic efficiency (7.8%) for NRR under ambient conditions. More importantly, the isotopic experiments using 15N2 as a nitrogen source confirm that the synthesized ammonia is derived from the direct supply of nitrogen. This result also demonstrates the possibility of high‐efficiency nitrogen reduction even though accompanied with vigorous hydrogen evolution.
Efficient Nonfullerene Organic Solar Cells with Small Driving Forces for Both Hole and Electron Transfer
Authors: Chen Shangshang , Wang Yuming , Zhang Lin , Zhao Jingbo , Chen Yuzhong , Zhu Danlei , Yao Huatong , Zhang Guangye , Ma Wei , Friend Richard H. , Chow Philip C. Y. , Gao Feng , Yan He
Published: October 2018

State‐of‐the‐art organic solar cells (OSCs) typically suffer from large voltage loss (Vloss) compared to their inorganic and perovskite counterparts. There are some successful attempts to reduce the Vloss by decreasing the energy offsets between the donor and acceptor materials, and the OSC community has demonstrated efficient systems with either small highest occupied molecular orbital (HOMO) offset or negligible lowest unoccupied molecular orbital (LUMO) offset between donors and acceptors. However, efficient OSCs based on a donor/acceptor system with both small HOMO and LUMO offsets have not been demonstrated simultaneously. In this work, an efficient nonfullerene OSC is reported based on a donor polymer named PffBT2T‐TT and a small‐molecular acceptor (O‐IDTBR), which have identical bandgaps and close energy levels. The Fourier‐transform photocurrent spectroscopy external quantum efficiency (FTPS‐EQE) spectrum of the blend overlaps with those of neat PffBT2T‐TT and O‐IDTBR, indicating the small driving forces for both hole and electron transfer. Meanwhile, the OSCs exhibit a high electroluminescence quantum efficiency (EQEEL) of ≈1 × 10−4, which leads to a significantly minimized nonradiative Vloss of 0.24 V. Despite the small driving forces and a low Vloss, a maximum EQE of 67% and a high power conversion efficiency of 10.4% can still be achieved.
Near‐Infrared Ternary Tandem Solar Cells
Authors: Li Yongxi , Lin Jiu‐Dong , Liu Xiao , Qu Yue , Wu Fu‐Peng , Liu Feng , Jiang Zuo‐Quan , Forrest Stephen R.
Published: October 2018

The paucity of near‐infrared (NIR) organic materials with high absorption at long wavelengths, combined with large diffusion lengths and charge mobilities, is an impediment to progress in achieving high‐efficiency organic tandem solar cells. Here a subcell is employed within a series tandem stack that comprises a solution‐processed ternary blend of two NIR‐absorbing nonfullerene acceptors and a polymer donor combined with a small‐molecular‐weight, short‐wavelength fullerene‐based subcell grown by vacuum thermal evaporation. The ternary cell achieves a power conversion efficiency of 12.6 ± 0.3% with a short‐circuit current of 25.5 ± 0.3 mA cm−2, an open‐circuit voltage of 0.69 ± 0.01 V, and a fill factor of 0.71 ± 0.01 under 1 sun, AM 1.5G spectral illumination. The success of this device is a result of the nearly identical offset energies between the lowest unoccupied molecular orbitals (LUMOs) of the donors with the highest occupied molecular orbital (HOMO) of the acceptor, resulting in a high open‐circuit voltage. A tandem structure with an antireflection coating combining these subcells demonstrates a power conversion efficiency of 15.4 ± 0.3%.
In Situ Li3PS4 Solid‐State Electrolyte Protection Layers for Superior Long‐Life and High‐Rate Lithium‐Metal Anodes
Authors: Liang Jianwen , Li Xiaona , Zhao Yang , Goncharova Lyudmila V. , Wang Gongming , Adair Keegan R. , Wang Changhong , Li Ruying , Zhu Yongchun , Qian Yitai , Zhang Li , Yang Rong , Lu Shigang , Sun Xueliang
Published: October 2018

A thin and adjustable Li3PS4 (LPS) solid‐state electrolyte protection layer on the surface of Li is proposed to address the dynamic plating/stripping process of Li metal. The LPS interlayer is formed by an in situ and self‐limiting reaction between P4S16 and Li in N‐methyl‐2‐pyrrolidone. By increasing the concentration of P4S16, the thickness of the LPS layer can be adjusted up to 60 nm. Due to the high ionic conductivity and low electrochemical activity of Li3PS4, the intimate protection layer of LPS can not only prevent the formation of Li dendrites, but also reduces parasitic side reactions and improves the electrochemical performance. As a result, symmetric cells with the LPS protection layer can deliver stable Li plating/stripping for 2000 h. Full cells assembled with the LPS‐protected Li exhibit two times higher capacity retention in Li–S batteries (≈800 mAh g−1) at 5 A g−1 for over 400 cycles compared to their bare Li counterparts. Furthermore, high rate performances can be achieved with Li‐LPS/LiCoO2 cells, which are capable of cycling at rates as high as 20 C. This innovative and scalable approach to stabilizing the Li anode can serve as a basis for the development of next‐generation high‐performance lithium‐metal batteries.
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

Fluorescent 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

Here 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

Polymeric 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

Iridium‐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.

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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

Recent 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

Low‐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

Single‐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

Herein, 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 Study

Nursery 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.

Methods

We 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 Results

Our 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.

Conclusions

Correlated 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.
First data from a parent‐reported registry of 81 individuals with Coffin–Siris syndrome: Natural history and management recommendations
Authors: Mannino Elizabeth A. , Miyawaki Hanae , Santen Gijs , Schrier Vergano Samantha A.
Published: October 2018

Coffin–Siris syndrome (CSS; MIM 135900) is a multisystem congenital anomaly syndrome caused by mutations in the genes in the Brg‐1 associated factors (BAF) complex. Classically, individuals with CSS have been described with hypo‐ or aplasia of the fifth digit nails or phalanges (hence the term “fifth digit syndrome”). Other physical features seen include growth restriction, coarse facial features, hypertrichosis or hirsutism, sparse scalp hair, dental anomalies, and other organ‐system abnormalities. Varying degrees of developmental and intellectual delay are universal. To date, approximately 200 individuals have been described in the literature. With the advent of large‐scale genetic testing such as whole‐exome sequencing is becoming more available, more individuals are being found to have mutations in this pathway, and the phenotypic spectrum appears to be broadening. We report here a large cohort of 81 individuals with the diagnosis of CSS from the first parent‐reported CSS/BAF complex registry in an effort to describe this variation among individuals, the natural history of the syndrome, and draw some gene–phenotype correlations. We propose that changes in the BAF complex may represent a spectrum of disorders, including both ARID1B‐related nonsyndromic intellectual disability (ARID1B‐ID) and CSS with classic physical features. In addition, we offer surveillance and management recommendations based on the medical issues encountered in this cohort to help guide physicians and patients' families.
Multicenter study of mortality in achondroplasia
Authors: Hashmi S. Shahrukh , Gamble Candace , Hoover‐Fong Julie , Alade Adekemi Yewande , Pauli Richard M. , Modaff Peggy , Carney Meagan , Brown Cassondra , Bober Michael B. , Hecht Jacqueline T.
Published: October 2018

Sudden death and higher mortality are recognized in achondroplasia, with acute brainstem compression, a common cause of mortality in children <4 years and cardiovascular deaths being more prevalent in adults. Although, changes in clinical management have improved survival, mortality is still higher than in the general population. The aim of this multicenter clinic‐based study was to assess the rate and causes of mortality in patients seen in clinic since 1986. Information was ascertained for achondroplasia patients clinically assessed in four skeletal dysplasia clinics. Data was sent to the National Death Index to identify vital status and cause of death. Standardized mortality rates (SMR) were calculated based on U.S. populations from 1975, 1995, and 2000. Eight hundred fifty‐five patients were identified, contributing 12,117 person‐years and a total of 12 deaths. One case died in infancy. In the 1–4 year age group, which had the highest age‐adjusted SMR, three out of five deaths were because of cerebrovascular/cardiovascular events. Half the deaths in ages 5 through 24 were because of accidental events, including motor vehicle accidents. Decreased mortality in children with achondroplasia was noted, particularly in younger age groups. This improvement in childhood survival is outpaced by improved survival in the general population. Causes of death in these patients have shifted over the last 30 years, with fewer sudden death and deaths because of pneumonia or hydrocephalus countered by more cardiovascular or cerebrovascular and accidental deaths. Clinicians should be aware of the apparent increased risk of vehicular accidents and counsel patients accordingly.
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

An 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

Lignin 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

Deoxyribozymes 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

Sterisch 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.