bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of SiC/Silica and Carbon/Silica Interfaces on the High‐Temperature Creep of Silicon Oxycarbide‐Based Glass Ceramics: A Case Study
Authors: Stabler Christina , Schliephake Daniel , Heilmaier Martin , Rouxel Tanguy , Kleebe Hans‐Joachim , Narisawa Masaki , Riedel Ralf , Ionescu Emanuel
Published: August 2018

In the present study, the high‐temperature creep behavior of three SiOC glass ceramics with different phase compositions are compared by the authors. All three SiOC glass ceramics have a vitreous silica matrix in common, but comprise different homogeneously dispersed phases: 1) only spherical β‐SiC nanoparticles (sample denoted hereafter SiC/SiO2), 2) only high‐aspect ratio sp2‐hybridized carbon (i.e., C/SiO2), and 3) both phases (SiC and segregated carbon, i.e., C/SiC/SiO2). Compression creep experiments are performed at temperatures in the range between 1100 and 1300 °C and true stresses of 50 to 200 MPa. The determined activation energy for creep of the SiOC glass ceramics of around 700 kJ mol−1 is independent of the phase composition. A stress exponent value of approximately 2 indicates an interface‐controlled deformation mechanism. All SiOC glass ceramics exhibit significantly higher creep viscosities than that of vitreous silica. Surprisingly, the spherical β‐SiC nanoparticles have a higher impact on the effective creep viscosities of SiOC as compared to that of the high‐aspect ratio segregated carbon phase. It is concluded that this originates from the β‐SiC/silica and C/silica interfaces, which have different effects on the creep behavior of silicon oxycarbide‐based glass ceramics.
Direct Bonding of Aluminum–Copper Metals through High‐Pressure Torsion Processing
Authors: Han Jae‐Kyung , Han Dae Kuen , Liang Guang Yuan , Jang Jae‐Il , Langdon Terence G. , Kawasaki Megumi
Published: August 2018

High‐pressure torsion (HPT) is used to investigate the formation of a new metal system by the direct bonding of separate disks of Al and Cu by processing at room temperature under a compressive pressure of 6.0 GPa and with increasing numbers of HPT turns up to 60. A detailed examination of the microstructure and a phase analysis reveal the presence of three intermetallic compounds, Al2Cu, AlCu, and Al4Cu9, in the nanostructured Al matrix with a grain size of ≈30 nm. Processing by HPT leads to the formation of a metal–matrix nanocomposite with extreme hardness near the edge of the Al–Cu disks after 60 HPT turns. Experiments show that the estimated wear rates exhibit an improvement in wear resistance while maintaining low wear rates for high applied loads up to ≈40–50 N under dry sliding conditions. The results confirm that there is a significant potential for using HPT processing in the joining and bonding of dissimilar metals at room temperature and in the expeditious fabrication of a wide range of new metal systems having enhanced mechanical and functional properties.
Carbon‐Based Photothermal Actuators
Authors: Han Bing , Zhang Yong‐Lai , Chen Qi‐Dai , Sun Hong‐Bo
Published: August 2018

Actuators that can convert environmental stimuli into mechanical work are widely used in intelligent systems, robots, and micromechanics. To produce robust and sensitive actuators of different scales, efforts are devoted to developing effective actuating schemes and functional materials for actuator design. Carbon‐based nanomaterials have emerged as preferred candidates for different actuating systems because of their low cost, ease of processing, mechanical strength, and excellent physical/chemical properties. Especially, due to their excellent photothermal activity, which includes both optical absorption and thermal conductivities, carbon‐based materials have shown great potential for use in photothermal actuators. Herein, the recent advances in photothermal actuators based on various carbon allotropes, including graphite, carbon nanotubes, amorphous carbon, graphene and its derivatives, are reviewed. Different photothermal actuating schemes, including photothermal effect–induced expansion, desorption, phase change, surface tension gradient creation, and actuation under magnetic levitation, are summarized, and the light‐to‐heat and heat‐to‐work conversion mechanisms are discussed. Carbon‐based photothermal actuators that feature high light‐to‐work conversion efficiency, mechanical robustness, and noncontact manipulation hold great promise for future autonomous systems.
Next‐Generation Narrow‐Band Green‐Emitting RbLi(Li3SiO4)2:Eu2+ Phosphor for Backlight Display Application
Authors: Zhao Ming , Liao Hongxu , Ning Lixin , Zhang Qinyuan , Liu Quanlin , Xia Zhiguo
Published: August 2018

The discovery of high efficiency narrow‐band green‐emitting phosphors is a major challenge in backlighting light‐emitting diodes (LEDs). Benefitting from highly condensed and rigid framework structure of UCr4C4‐type compounds, a next‐generation narrow green emitter, RbLi(Li3SiO4)2:Eu2+ (RLSO:Eu2+), has emerged in the oxide‐based family with superior luminescence properties. RLSO:Eu2+ phosphor can be efficiently excited by GaN‐based blue LEDs, and shows green emission at 530 nm with a narrow full width at half maximum of 42 nm, and very low thermal quenching (103%@150 °C of the integrated emission intensity at 20 °C), however its chemical stability needs to be improved later. The white LED backlight using optimized RLSO:8%Eu2+ phosphor demonstrates a high luminous efficacy of 97.28 lm W−1 and a wide color gamut (107% National Television System Committee standard (NTSC) in Commission Internationale de L'Eclairage (CIE) 1931 color space), suggesting its great potential for industrial applications as liquid crystal display (LCD) backlighting.
Soft Electronically Functional Polymeric Composite Materials for a Flexible and Stretchable Digital Future
Authors: Tee Benjamin C. K. , Ouyang Jianyong
Published: August 2018

Flexible/stretchable electronic devices and systems are attracting great attention because they can have important applications in many areas, such as artificial intelligent (AI) robotics, brain–machine interfaces, medical devices, structural and environmental monitoring, and healthcare. In addition to the electronic performance, the electronic devices and systems should be mechanically flexible or even stretchable. Traditional electronic materials including metals and semiconductors usually have poor mechanical flexibility and very limited elasticity. Three main strategies are adopted for the development of flexible/stretchable electronic materials. One is to use organic or polymeric materials. These materials are flexible, and their elasticity can be improved through chemical modification or composition formation with plasticizers or elastomers. Another strategy is to exploit nanometer‐scale materials. Many inorganic materials in nanometer sizes can have high flexibility. They can be stretchable through the composition formation with elastomers. Ionogels can be considered as the third type of materials because they can be stretchable and ionically conductive. This article provides the recent progress of soft functional materials development including intrinsically conductive polymers for flexible/stretchable electrodes, and thermoelectric conversion and polymer composites for large area, flexible stretchable electrodes, and tactile sensors.
Morphology Control Enables Efficient Ternary Organic Solar Cells
Authors: Xie Yuanpeng , Yang Fan , Li Yuxiang , Uddin Mohammad Afsar , Bi Pengqing , Fan Bingbing , Cai Yunhao , Hao Xiaotao , Woo Han Young , Li Weiwei , Liu Feng , Sun Yanming
Published: August 2018

Ternary organic solar cells are promising alternatives to the binary counterpart due to their potential in achieving high performance. Although a growing number of ternary organic solar cells are recently reported, less effort is devoted to morphology control. Here, ternary organic solar cells are fabricated using a wide‐bandgap polymer PBT1‐C as the donor, a crystalline fused‐ring electron acceptor ITIC‐2Cl, and an amorphous fullerene derivative indene‐C60 bisadduct (ICBA) as the acceptor. It is found that ICBA can disturb π–π interactions of the crystalline ITIC‐2Cl molecules in ternary blends and then help to form more uniform morphology. As a result, incorporation of 20% ICBA in the PBT1‐C:ITIC‐2Cl blend enables efficient charge dissociation, negligible bimolecular recombination, and balanced charge carrier mobilities. An impressive power conversion efficiency (PCE) of 13.4%, with a high fill factor (FF) of 76.8%, is eventually achieved, which represents one of the highest PCEs reported so far for organic solar cells. The results manifest that the adoption of amorphous fullerene acceptor is an effective approach to optimizing the ternary blend morphology and thereby increases the solar cell performance.
Semimetal–Semiconductor Transitions for Monolayer Antimonene Nanosheets and Their Application in Perovskite Solar Cells
Authors: Zhang Fan , He Junjie , Xiang Yuren , Zheng Kai , Xue Bin , Ye Shuai , Peng Xiao , Hao Yuying , Lian Jiarong , Zeng Pengju , Qu Junle , Song Jun
Published: August 2018

Antimonene‐based 2D materials are attracting increasing research interest due to their superior physicochemical properties and promising applications in next‐generation electronics and optoelectronics devices. However, the semiconductor properties of antimonene are still at the theoretical simulation stage and are not experimentally verified, significantly restricting its applications in specific areas. In this study, the semiconductor properties of monolayer antimonene nanosheets are experimentally verified. It is found that the obtained semiconductive antimonene nanosheets (SANs) exhibit indirect bandgap properties, with photoluminescence (PL) bandgap at about 2.33 eV and PL lifetime of 4.3 ns. Moreover, the obtained SANs are ideal for the hole extraction layer in planar inverted perovskite solar cells (PVSCs) and significantly enhance the device performance due to fast hole extraction and efficient hole transfer at the perovskite/hole transport layer interface. Overall, these findings look promising for the future prospects of antimonene in electronics and optoelectronics.
Interfacially Polymerized Particles with Heterostructured Nanopores for Glycopeptide Separation
Authors: Song Yongyang , Li Xiuling , Fan Jun‐Bing , Kang Hongjian , Zhang Xiaofei , Chen Cheng , Liang Xinmiao , Wang Shutao
Published: August 2018

Porous polymer materials are extensively used for biomolecule separation. However, conventional homogeneous porous polymer materials cannot efficiently separate specific low‐abundance biomolecules from complex samples. Here, particles fabricated by emulsion interfacial polymerization featuring heterostructured nanopores with tunable size are reported, which can be used to realize low‐abundance glycopeptide (GP) separation from complex biofluids. The heterostructured surface inside the nanopores allows solvent‐dependent local adsorption of biomolecules onto hydrophilic or hydrophobic regions. Low‐abundance hydrophilic GPs in complex biofluids can be efficiently separated via the hydrophilic region of nanopores in low‐polarity solvent after the hydrophobic region removes high‐abundance hydrophobic proteins and non‐glycopeptides in high‐polarity solvent. It is expected that these particles with heterostructured nanopores can be used for separation of nucleic acids, saccharides, and proteins, and downstream clinical diagnosis.
Raising the Working Temperature of a Triboelectric Nanogenerator by Quenching Down Electron Thermionic Emission in Contact‐Electrification
Authors: Xu Cheng , Wang Aurelia Chi , Zou Haiyang , Zhang Binbin , Zhang Chunli , Zi Yunlong , Pan Lun , Wang Peihong , Feng Peizhong , Lin Zhiqun , Wang Zhong Lin
Published: August 2018

As previously demonstrated, contact‐electrification (CE) is strongly dependent on temperature, however the highest temperature in which a triboelectric nanogenerator (TENG) can still function is unknown. Here, by designing and preparing a rotating free‐standing mode Ti/SiO2 TENG, the relationship between CE and temperature is revealed. It is found that the dominant deterring factor of CE at high temperatures is the electron thermionic emission. Although it is normally difficult for CE to occur at temperatures higher than 583 K, the working temperature of the rotating TENG can be raised to 673 K when thermionic emission is prevented by direct physical contact of the two materials via preannealing. The surface states model is proposed for explaining the experimental phenomenon. Moreover, the developed electron cloud‐potential well model accounts for the CE mechanism with temperature effects for all types of materials. The model indicates that besides thermionic emission of electrons, the atomic thermal vibration also influences CE. This study is fundamentally important for understanding triboelectrification, which will impact the design and improve the TENG for practical applications in a high temperature environment.
All‐Solution‐Processed Pure Formamidinium‐Based Perovskite Light‐Emitting Diodes
Authors: Wang Juanhong , Song Chen , He Zhiwei , Mai Chaohuang , Xie Gancheng , Mu Lan , Cun Yangke , Li Jiali , Wang Jian , Peng Junbiao , Cao Yong
Published: August 2018

All‐solution‐processed pure formamidinium‐based perovskite light‐emitting diodes (PeLEDs) with record performance are successfully realized. It is found that the FAPbBr3 device is hole dominant. To achieve charge carrier balance, on the anode side, PEDOT:PSS 8000 is employed as the hole injection layer, replacing PEDOT:PSS 4083 to suppress the hole current. On the cathode side, the solution‐processed ZnO nanoparticle (NP) is used as the electron injection layer in regular PeLEDs to improve the electron current. With the smallest ZnO NPs (2.9 nm) as electron injection layer (EIL), the solution‐processed PeLED exhibits a highest forward viewing power efficiency of 22.3 lm W−1, a peak current efficiency of 21.3 cd A−1, and an external quantum efficiency of 4.66%. The maximum brightness reaches a record 1.09 × 105 cd m−2. A record lifetime T50 of 436 s is achieved at the initial brightness of 10 000 cd m−2. Not only do PEDOT:PSS 8000 HIL and ZnO NPs EIL modulate the injected charge carriers to reach charge balance, but also they prevent the exciton quenching at the interface between the charge injection layer and the light emission layer. The subbandgap turn‐on voltage is attributed to Auger‐assisted energy up‐conversion process.
Plasmon‐Tunable Tip Pyramids: Monopole Nanoantennas for Near‐Field Scanning Optical Microscopy
Authors: Vasconcelos Thiago L. , Archanjo Bráulio S. , Oliveira Bruno S. , Valaski Rogério , Cordeiro Rafael C. , Medeiros Helton G. , Rabelo Cassiano , Ribeiro Aroldo , Ercius Peter , Achete Carlos A. , Jorio Ado , Cançado Luiz Gustavo
Published: August 2018

Squeezing optical fields into nanometer scale is the key step to perform spatially resolved near‐field optics. In scattering‐type near‐field optical microscopy, this task is accomplished by nanoantennas that convert propagating radiation to local near‐fields and vice versa. The usual nanoantenna is composed by an elongated metal structure whose longitudinal dimension is scaled to support dipole modes of localized surface plasmon resonances. However, monopole modes can also be explored if the elongated metal nanoparticle is electrically grounded on a flat metallic plateau that acts like a mirror providing the monopole's image that closes the dipole system. Here, a method for batch production of monopole nanoantennas for scattering‐type near‐field scanning optical microscopy is presented. The nanoantennas are composed of a micropyramidal body with a nanopyramidal end whose lateral dimension can be scaled to fine‐tune localized surface plasmon resonance modes. The monopole character of the nanoantennas is revealed by electron energy loss spectroscopy, and their efficiency and reproducibility are tested in tip‐enhanced Raman spectroscopy experiments performed on single‐layer graphene and single‐walled carbon nanotubes.
Copper‐Catalyzed Defluorinative Thioannulation of Trifluoropropynes for the Synthesis of 1,2‐Dithiole‐3‐thiones
Authors: Wei Feng , Shen Xiao‐Qin , Zhang Xiao‐Hong , Zhang Xing‐Guo
Published: August 2018

A simple and practical strategy for the preparation of 1,2‐dithiole‐3‐thionesviacopper‐catalyzed defluorinative thioannulation of trifluoropropynes has been developed using elemental sulfur as the sole sulfur source. This reaction displays a wide substrate scope and high functional group tolerance to afford the corresponding S‐heterocycles in moderate to good yields and features efficient construction of multiple C−S bonds through C−F bond cleavage of CF3groups.

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Selective Hydroarylation of 1,3‐Diynes Using a Dimeric Manganese Catalyst: Modular Synthesis of Z‐Enynes
Authors: Yan Zhongfei , Yuan Xiang‐Ai , Zhao Yue , Zhu Chengjian , Xie Jin
Published: August 2018

The transition‐metal‐catalyzed selective hydroarylation of unsymmetrical alkynes represents the state‐of‐art in organic chemistry, and still mainly relies on the use of precious late‐transition‐metal catalysts. Reported herein is an unprecedented MnI‐catalyzed hydroarylation of unsymmetrical 1,3‐diyne alcohols with commercially available arylboronic acids with predictive selectivity. This method addresses the challenges in regio‐, stereo‐, and chemoselectivity. It offers a general, convenient and practical strategy for the modular synthesis of multisubstituted Z‐configurated conjugated enynes. This protocol is distinguished by its operational simplicity, complete selectivity, excellent functional‐group compatibility, and gram‐scale potential. A dimeric MnI species, Mn2(CO)8Br2, was proven to be a much more efficient catalyst precursor than Mn(CO)5Br.
High‐Capacity Upconversion Wavelength and Lifetime Binary Encoding for Multiplexed Biodetection
Authors: Zhou Lei , Fan Yong , Wang Rui , Li Xiaomin , Fan Lingling , Zhang Fan
Published: August 2018

Optical multiplexing plays an important role in fields ranging from advanced biological assays to security. However, conventional codes based on fluorescent color and intensity are limited to spectral overlap and background interference. Herein, we present a new multiplexing concept by manipulating the luminescence emission color and decay lifetimes of upconversion nanoparticles (τλ‐UCNPs) separately for the first time through designing the core/multi‐shell structure and controlled energy relay method. This new color/lifetime binary strategy exhibits exponentially scalable encoding capacity (>105), three orders of magnitudes higher than that of conventional color/intensity way. The strategy enables the multiplexed detection of human papilloma virus (HPV) subtypes in patient samples and robust anti‐counterfeiting. This work opens new opportunities for optical multiplexing with luminescent materials.
Regioselektive metall‐ und reagenzfreie Arylierung von Benzothiophenen durch dehydrierende Elektrosynthese
Authors: Lips Sebastian , Schollmeyer Dieter , Franke Robert , Waldvogel Siegfried R.
Published: August 2018

Eine neue Strategie für die Synthese von Biarylverbindungen, die aus einer Benzothiophen‐ und einer Phenoleinheit bestehen, wird berichtet. Diese Heterobiaryle sind für pharmazeutische, biologische und leistungsfähige optoelektronische Anwendungen von großem Interesse. Durch ein metall‐ und reagenzfreies, elektrosynthetisches und hochwirksames Verfahren werden 2‐ oder 3‐(Hydroxyphenyl)benzo[b]thiophene regioselektiv gewonnen. Die beschriebene einstufige Synthese ist einfach durchzuführen, skalierbar und inhärent sicher. Die Produkte werden in hohen Ausbeuten bis zu 88 % und hervorragender Selektivität isoliert. Das Verfahren zeichnet sich zudem durch ein breites Eduktspektrum aus und toleriert eine Vielzahl von funktionellen Gruppen.
Hydrogenation of CO2‐Derived Carbonates and Polycarbonates to Methanol and Diols by Metal–Ligand Cooperative Manganese Catalysis
Authors: Zubar Viktoriia , Lebedev Yury , Azofra Luis Miguel , Cavallo Luigi , El‐Sepelgy Osama , Rueping Magnus
Published: August 2018

The first base‐metal‐catalysed hydrogenation of CO2‐derived carbonates to alcohols is presented. The reaction proceeds under mild conditions in the presence of a well‐defined manganese complex with a loading as low as 0.25 mol %. The non‐precious‐metal homogenous catalytic system provides an indirect route for the conversion of CO2 into methanol with the co‐production of value‐added (vicinal) diols in yields of up to 99 %. Experimental and computational studies indicate a metal–ligand cooperative catalysis mechanism.
Spirofused and Annulated 1,2,4‐Trioxepane‐, 1,2,4‐Trioxocane‐, and 1,2,4‐Trioxonane‐Cyclohexadienones: Cyclic Peroxides with Unusual Ring Conformation Dynamics
Authors: Eske Angelika , Ecker Sabrina , Fendinger Carolina , Goldfuss Bernd , Jonen Matthis , Lefarth Jens , Neudörfl Jörg‐M. , Spilles Matthias , Griesbeck Axel G.
Published: August 2018

C3‐ or C4‐hydroxyalkylated phenols are highly reactive towards peroxidation with oxone, which results in the formation of tertiary C3 hydroperoxides. This reaction can also be performed with photochemically generated singlet oxygen. However, other characteristic singlet oxygen reactions do not proceed with caroate. The initially formed hydroperoxides cyclize in the presence of a Lewis acid catalyst based on boron, indium, or iron to give spiroannulated peroxides. These exhibit restricted ring inversion whereas larger nine‐membered‐ring peroxides are thermally less stable and show higher ring flexibility (according to NMR analysis).
Modular Redesign of a Cationic Lytic Peptide To Promote the Endosomal Escape of Biomacromolecules
Authors: Azuma Yusuke , Imai Haruka , Kawaguchi Yoshimasa , Nakase Ikuhiko , Kimura Hiroshi , Futaki Shiroh
Published: August 2018

Endocytosis is an important route for the intracellular delivery of biomacromolecules, wherein their inefficient endosomal escape into the cytosol remains a major barrier. Based on the understanding that endosomal membranes are negatively charged, we focused on the potential of cationic lytic peptides for developing endosomolysis agents to release such entrapped molecules. As such, a venom peptide, Mastoparan X, was employed and redesigned to serve as a delivery tool. Appending a tri‐glutamate unit to the N‐terminus attenuates the cytotoxicity of Mastoparan X by about 40 fold, while introduction of a NiII‐dipicolylamine complex enhances cellular uptake of the peptide by about 17 fold. Using the optimized peptide, various fluorescently labeled macromolecules were successfully delivered to the cytosol, enabling live‐cell imaging of acetylated histones.
Plant RuBisCo: An Underutilized Protein for Food Applications
Authors: Di Stefano Elisa , Agyei Dominic , Njoku Emmanuel N. , Udenigwe Chibuike C.
Published: August 2018

Malnutrition is a public health concern and chronic protein malnutrition is prevalent in early childhood in many developing countries. Plant proteins are good candidates for meeting the growing protein needs. RuBisCo (ribulose‐1,5‐bisphosphate carboxylase/oxygenase) is a photosynthetic enzyme that exists in 4 forms (I, II, III, and IV), with form I being characteristic of higher plants. Form I RuBisCo represents 50% of leaf proteins, and is, therefore, important as a source of protein for nutrition and as a functional ingredient, although the laborious extraction process for plant proteins can limit their use in food products. Column chromatography is the most effective RuBisCo purification step for laboratory research, while ultrafiltration has shown prospects for large‐scale applications. RuBisCo has excellent solubility in alkaline pH and at low denaturation temperatures. Thus, RuBisCo can form brittle gels at low concentrations, which can influence the chemosensory properties of products containing the proteins. Foaming of RuBisCo occurs around its isoelectric point, while emulsifying capacity proportionally increases with pH. Heating prior to emulsification increased the strength and stability of emulsion formed with RuBisCo. The protein is also attractive due to its high nutritional values and in vitro digestibility. Furthermore, RuBisCo is a competitive source of bioactive peptides with opioid‐like, memory‐enhancing, appetite‐stimulating, antioxidative, and antihypertensive properties, demonstrating the wide range of food applications where RuBisCo can be utilized.
Double layer aligned‐graphene nanosheets/styrene‐butadiene rubber composites: Tribological and mechanical properties
Authors: Wang Fei , Mao Jian
Published: August 2018

We enhanced tribological and mechanical properties of styrene‐butadiene rubber (SBR) by designing double layer aligned‐graphene nanosheets (aligned‐GNSs)/SBR composites with one‐step emulsion polymerization preparation method. The composites consisted of two layers, one is the SBR layer and the other is aligned‐GNSs/SBR layer, in which the graphene nanosheets (GNSs) regularly aligned. The resulted composites exhibited mega increase of tribological property as well as mechanical property. With the increase of GNSs contents from 0.5 to 5 wt %, both the friction coefficient and volume wear rate steadily declined, and the mechanics dramatically increased. Such as 59% decrease of friction coefficient and 1778% increase of the initial tensile modulus when the addition of GNSs is 5 wt %. The above results are mainly due to the well aligned‐GNSs in SBR, which can take full advantage of the unique properties of GNSs two‐dimensional materials. The detailed mechanisms of improving tribological and mechanical properties were discussed in the study. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 46939.
Die‐offs of the endangered pearl mussel Margaritifera margaritifera during an extreme drought
Authors: Sousa Ronaldo , Ferreira André , Carvalho Francisco , Lopes‐Lima Manuel , Varandas Simone , Teixeira Amílcar
Published: August 2018

Droughts may be responsible for important ecological impacts in freshwater ecosystems, including the death of rare species.

This study assessed the mortality of the endangered pearl mussel Margaritifera margaritifera (Linnaeus, 1758) in the Mente, Rabaçal and Tuela rivers (north west of the Iberian Peninsula) during the extreme summer drought of 2017.

Mortality occurred as a result of the low river flow, which led to mussel stranding near the banks and consumption (by predation or scavenging) by wild boar Sus scrofa (Linnaeus, 1758).

Mortality differed across sites. The shell lengths of live mussels (measured before the drought) and dead mussels significantly differed in the Rabaçal River, but not in the Mente and Tuela rivers.

Extreme droughts are predicted to increase in number and intensity in the future, and possible impacts on rare species such as M. margaritifera should be carefully monitored. Several M. margaritifera populations in Iberia (and elsewhere) may now be at increased risk, and measures should be implemented in order to mitigate the impacts of future extreme droughts.
The effect of regional sea surface temperature rise on fisheries along the Portuguese Iberian Atlantic coast
Authors: Leitão Francisco , Maharaj Ravi R. , Vieira Vasco M.N.C.S. , Teodósio Alexandra , Cheung William W.L.
Published: August 2018

The environmental effects of climate change are expected to impact fisheries, and related economies, and represent a significant challenge for the development of government policy. The impact of ocean warming on fisheries yields is of particular concern.

The effect of sea surface temperature (SST) on fisheries in three distinct biogeographic areas (north‐western, NW; south‐western, SW; and south, S) and different fleet sectors (trawl, seine, and multi‐gear) of the Portuguese coast was examined.

The mean temperature of the catch (MTC) was applied to the official landings statistics to assess the effect of global warming on the exploited marine communities. MTC increased from 16.9, 16.7, and 17.4°C in 1989 to 17.9, 18.1, and 18.3°C in 2009, whereas the linear rate of MTC increase was 0.54, 0.49, and 0.70°C per decade in the NW, SW, and S regions, respectively.

The increase of warmer species in fisheries landings is regional‐specific. The percentage increases in landings of warmer water species increased significantly from north to south: 5.1, 6.7, and 18% per decade in the NW, SW, and S, respectively.

The results confirmed that ocean warming has affected the composition of fisheries landings (of warmer and colder species) in the three regions of the Portuguese coast. The results highlight the importance and urgency of considering the temperature‐induced shift in species distribution in fisheries management.
The Alliance for Freshwater Life: A global call to unite efforts for freshwater biodiversity science and conservation
Authors: Darwall William , Bremerich Vanessa , De Wever Aaike , Dell Anthony I. , Freyhof Jörg , Gessner Mark O. , Grossart Hans‐Peter , Harrison Ian , Irvine Ken , Jähnig Sonja C. , Jeschke Jonathan M. , Lee Jessica J. , Lu Cai , Lewandowska Aleksandra M. , Monaghan Michael T. , Nejstgaard Jens C. , Patricio Harmony , Schmidt‐Kloiber Astrid , Stuart Simon N. , Thieme Michele , Tockner Klement , Turak Eren , Weyl Olaf
Published: August 2018

Global pressures on freshwater ecosystems are high and rising. Viewed primarily as a resource for humans, current practices of water use have led to catastrophic declines in freshwater species and the degradation of freshwater ecosystems, including their genetic and functional diversity. Approximately three‐quarters of the world's inland wetlands have been lost, one‐third of the 28 000 freshwater species assessed for the International Union for Conservation of Nature (IUCN) Red List are threatened with extinction, and freshwater vertebrate populations are undergoing declines that are more rapid than those of terrestrial and marine species. This global loss continues unchecked, despite the importance of freshwater ecosystems as a source of clean water, food, livelihoods, recreation, and inspiration.

The causes of these declines include hydrological alterations, habitat degradation and loss, overexploitation, invasive species, pollution, and the multiple impacts of climate change. Although there are policy initiatives that aim to protect freshwater life, these are rarely implemented with sufficient conviction and enforcement. Policies that focus on the development and management of fresh waters as a resource for people almost universally neglect the biodiversity that they contain.

Here we introduce the Alliance for Freshwater Life, a global initiative, uniting specialists in research, data synthesis, conservation, education and outreach, and policymaking. This expert network aims to provide the critical mass required for the effective representation of freshwater biodiversity at policy meetings, to develop solutions balancing the needs of development and conservation, and to better convey the important role freshwater ecosystems play in human well‐being. Through this united effort we hope to reverse this tide of loss and decline in freshwater biodiversity. We introduce several short‐ and medium‐term actions as examples for making positive change, and invite individuals, organizations, authorities, and governments to join the Alliance for Freshwater Life.
Discovery of the Romanesque church of the Abbey of our lady of Bec (Le Bec‐Hellouin, Normandy, France) by means of geophysical methods
Authors: Fauchard Cyrille , Saley Abdoulaziz Djibrila , Camerlynck Christian , Fargier Yannick , Antoine Raphael , Thérain Paul‐Franck
Published: August 2018

A geophysical survey was carried out in 2015 for the development of the patrimonial site of the Abbey of Our Lady of Bec (also called the Bec Abbey), located in Le Bec‐Héllouin, Normandy, France. This survey aimed at optimizing the future accessibility programme by preserving the historical heritage of the Bec Abbey, taking into account potential underground remains. The ground penetrating radar (GPR), the electrical resistivity imaging (ERI) and the magnetic method (MM) were used to prospect the shallow surface. The GPR imaging shows longitudinal and curvated structures, drawing the classical and simplified plan of a Romanesque church basement of the eleventh century. This is the most important discovery of this survey, since the existence of this church was historically known but has remained unlocated till this geophysical survey. The ERI measurements confirm and locally complete most of the GPR results. Despite the very magnetic‐noisy environment, the MM investigation is the only method detecting a longitudinal structure that can be the foundation of an ancient wall between the Saint Nicolas' tower and the church nave of the thirteenth century. Finally, authorities recently allowed in July 2017 the publication of excavations performed by archaeologists. Most of the geophysical anomalies have helped to target the archaeological investigation and the results provide a detailled interpretation in terms of depth and nature of remnants. Archaeological investigation then offers an important historical outcome of the various stages of construction and destruction of the Bec Abbey.
How Acts of Infidelity Promote DNA Break Repair: Collision and Collusion Between DNA Repair and Transcription
Authors: Sivaramakrishnan Priya , Gordon Alasdair J. E. , Halliday Jennifer A. , Herman Christophe
Published: August 2018

Transcription is a fundamental cellular process and the first step in gene regulation. Although RNA polymerase (RNAP) is highly processive, in growing cells the progression of transcription can be hindered by obstacles on the DNA template, such as damaged DNA. The authors recent findings highlight a trade‐off between transcription fidelity and DNA break repair. While a lot of work has focused on the interaction between transcription and nucleotide excision repair, less is known about how transcription influences the repair of DNA breaks. The authors suggest that when the cell experiences stress from DNA breaks, the control of RNAP processivity affects the balance between preserving transcription integrity and DNA repair. Here, how the conflict between transcription and DNA double‐strand break (DSB) repair threatens the integrity of both RNA and DNA are discussed. In reviewing this field, the authors speculate on cellular paradigms where this equilibrium is well sustained, and instances where the maintenance of transcription fidelity is favored over genome stability.
An approximate Bayesian significance test for genomic evaluations
Authors: Wittenburg Dörte , Liebscher Volkmar
Published: August 2018

Genomic information can be used to study the genetic architecture of some trait. Not only the size of the genetic effect captured by molecular markers and their position on the genome but also the mode of inheritance, which might be additive or dominant, and the presence of interactions are interesting parameters. When searching for interacting loci, estimating the effect size and determining the significant marker pairs increases the computational burden in terms of speed and memory allocation dramatically. This study revisits a rapid Bayesian approach (fastbayes). As a novel contribution, a measure of evidence is derived to select markers with effect significantly different from zero. It is based on the credibility of the highest posterior density interval next to zero in a marginalized manner. This methodology is applied to simulated data resembling a dairy cattle population in order to verify the sensitivity of testing for a given range of type‐I error levels. A real data application complements this study. Sensitivity and specificity of fastbayes were similar to a variational Bayesian method, and a further reduction of computing time could be achieved. More than 50% of the simulated causative variants were identified. The most complex model containing different kinds of genetic effects and their pairwise interactions yielded the best outcome over a range of type‐I error levels. The validation study showed that fastbayes is a dual‐purpose tool for genomic inferences – it is applicable to predict future outcome of not‐yet phenotyped individuals with high precision as well as to estimate and test single‐marker effects. Furthermore, it allows the estimation of billions of interaction effects.
Spectroscopic investigations of nanosized Cr3+ doped Sc2−xInx(WO4)3: A new promising laser material
Authors: Yordanova A. , Iordanova R. , Koseva I. , Nikolov V. , Kukeva R.
Published: August 2018

Chromium(III) doped nanosized Sc2−xInx(WO4)3, (x = 0–2) solid solutions were prepared by the co‐precipitation/calcination method. The obtained powders were characterized using X‐ray diffraction (XRD), electron paramagnetic resonance (EPR), infrared (IR), absorption and luminescence spectra. X‐ray analysis showed that the compounds are pure solid solutions with orthorhombic symmetry at x values 0 and 0.5 and with monoclinic symmetry for x values 1.0, 1.5 and 2.0. The calculated crystallite size ranged from about 20 to 110 nm, except for Sc2(WO4)3 characterized by considerably larger sizes. IR spectra of the solid solutions contain the characteristic vibrations of the WO4 and MeO6, (Me = Sc, In) polyhedra, building the Sc2(WO4)3 and In2(WO4)3 structures. EPR analysis proved the presence of isolated Cr3+ ions in the crystal field with rhombic symmetry. The presence of Cr3+ in sites with weak and strong crystal field was revealed by absorption and luminescence spectra. This study demonstrates the effect of hosts crystal symmetry, particles size and doping concentration on the luminescence properties.
Optimization of extraction and analytical protocol for mass spectrometry‐based metabolomics analysis of hepatotoxicity
Authors: Yang Rui , Zhao Qi , Hu Dan‐Dan , Xiao Xue‐Rong , Li Fei
Published: August 2018

Drug‐induced liver injury is a clinically leading side‐effect of drugs. In the present study, a liquid chromatography mass spectrometry‐based metabolomics protocol was optimized for extraction and analysis of endogenous metabolites from liver tissue during hepatotoxicity. Various extraction solutions, resuspension solutions, extraction folds and dissolution methods for the supernatant were compared using the number of extracted total ions, relative response and relative extraction efficiency of targeted metabolites from liver tissue. The polar and nonpolar endogenous metabolites associated with liver injury were analyzed by hydrophilic interaction chromatography and reversed‐phase liquid chromatography with UPLC–QTOFMS. The results indicated that extraction with 10‐fold 50% acetonitrile in water and the supernatant diluted (1:1) with 100% acetonitrile rather than resuspension was the optimal extraction protocol. Subsequently, the optimized method was able to examine the change in metabolites in mouse liver tissue resulting from treatment with a toxic natural product, toosendanin. Taken together, the optimized extraction and analytical protocol provides high reliability and reproducibility for polar and nonpolar metabolites in liver tissue and may be suitable for metabolomics analysis of liver injury induced by drugs or chemicals.
Coexpression of 5‐Aminolevulinic Acid Synthase Gene Facilitates Heterologous Production of Thermostable Cytochrome P450, CYP119, in Holo Form in Escherichia coli
Authors: Honda Yuki , Nanasawa Kii , Fujii Hiroshi
Published: August 2018

Cytochrome P450 enzymes are heme‐containing monooxygenases that exhibit potential as biocatalysts for practical applications. The Escherichia coli expression system is frequently used for biocatalyst production; however, heterologous production of hemeproteins in their holo form is difficult due to insufficient heme synthesis by the host. In this study, 5‐aminolevulinic acid synthase (ALAS) from Rhodobacter capsulatus is used to accelerate intracellular heme biosynthesis in E. coli; this demonstrates that coexpression of the ALAS gene (ALAS) improves the heterologous production of cytochrome P450, CYP119, from Sulfolobus acidocaldarius. Coexpression of ALAS increased the amount of heterologous CYP119 isolated and the ratio of its holo form. The ratio of holo‐CYP119 resulting from the coexpression of ALAS in E. coli was 99 %, whereas that from cells expressing CYP119 exclusively was 66 %. Coexpression of ALAS is a promising alternative for the efficient heterologous production of hemeproteins by using E. coli.
Fingerprinting Biogenic Aldehydes through Pattern Recognition Analyses of Excitation–Emission Matrices
Authors: Lazurko Caitlin , Radonjic Ivana , Suchý Mojmír , Liu George , Rolland‐Lagan Anne‐Gaëlle , Shuhendler Adam
Published: August 2018

Biogenic carbonyls, especially aldehydes, have previously demonstrated their potential to serve as early diagnostic biomarkers for disease and injury that have not been fully realized owing, in part, to the lack of a rapid and simple point‐of‐care method for aldehyde identification. The ability to determine which carbonyl compound is elevated and not just the total aldehydic load may provide more disease‐ or injury‐specific diagnostic information. Toward this end, a novel fluorophore is presented that is able to form a complex with biogenic carbonyls under catalyst‐free conditions so as to give a fluorescent fingerprint of the resulting hydrazone. The successful identification of bound carbonyls was accomplished with a newly described algorithm that applied principal curvature analysis of excitation–emission matrices to reduce surface features to ellipse representations, followed by a pattern‐matching routine. With this algorithm, carbonyls were identified over a range of concentrations, and mixture components were successfully parsed. Overall, the results presented lay the groundwork for novel implementations of chemometrics to low‐cost, rapid, and simple‐to‐implement point‐of‐care diagnostics.
Layered Heterostructures of Ultrathin Polymeric Carbon Nitride and ZnIn2S4 Nanosheets for Photocatalytic CO2 Reduction
Authors: Zhou Min , Wang Sibo , Yang Pengju , Luo Zhishan , Yuan Rusheng , Asiri Abdullah M. , Wakeel Muhammad , Wang Xinchen
Published: August 2018

The rational construction of heterostructures by using layered semiconductors with two‐dimensional (2D) nanosheet configurations is promising to improve the efficiency of CO2 photoreduction. Herein, the fabrication of layered heterojunction photocatalysts (PCN/ZnIn2S4) by in situ growth of 2D ZnIn2S4 nanosheets on the surfaces of ultrathin polymeric carbon nitride (PCN) layers is presented for greatly enhanced CO2 conversion with visible light. The solution‐processed self‐assembly strategy renders the building of uniform and intimate junctions between PCN layers and ZnIn2S4 subunits, which remarkably accelerates the separation and transfer of photogenerated charge carriers. In addition, the layered composites can also promote CO2 adsorption and strengthen the visible‐light absorption. Consequently, the optimized PCN/ZnIn2S4 sheet‐shaped composite shows reinforced photoactivity for deoxygenative CO2 conversion, affording a high CO‐production rate of 44.6 μmol h−1, which is 223 times higher than that of the pristine PCN nanosheets. Moreover, the heterojunction photocatalyst also exhibits high stability during repeated runs for five cycles.
Unique Stereoselective Homolytic C−O Bond Activation in Diketopiperazine‐Derived Alkoxyamines by Adjacent Amide Pyramidalization
Authors: Amatov Tynchtyk , Jangra Harish , Pohl Radek , Cisařová Ivana , Zipse Hendrik , Jahn Ullrich
Published: August 2018

Simple monocyclic diketopiperazine (DKP)‐derived alkoxyamines exhibit unprecedented activation of a remote C−O bond for homolysis by amide distortion. The combination of strain‐release‐driven amide planarization and the persistent radical effect (PRE) enables a unique, irreversible, and quantitative trans→cis isomerization under much milder conditions than typically observed for such homolysis‐limited reactions. This isomerization is shown to be general and independent of the steric and electronic nature of both the amino acid side chains and the substituents at the DKP nitrogen atoms. Homolysis rate constants are determined, and they significantly differ for both the labile trans diastereomers and the stable cis diastereomers. To reveal the factors influencing this unusual process, structural features of the kinetic trans diastereomers and thermodynamic cis diastereomers are investigated in the solid state and in solution. X‐ray crystallographic analysis and computational studies indicate substantial distortion of the amide bond from planarity in the trans‐alkoxyamines, and this is believed to be the cause for the facile and quantitative isomerization. Thus, these amino‐acid‐derived alkoxyamines are the first examples that exhibit a large thermodynamic preference for one diastereomer over the other upon thermal homolysis, and this allows controlled switching of configurations and configurational cycling.
Investigating the Thermal Stability of Organic Thin‐Film Transistors and Phototransistors Based on [1]‐Benzothieno‐[3,2‐b]‐[1]‐benzothiophene Dimeric Derivatives
Authors: He Yu , Guo Shenghui , He Yaowu , Murtaza Imran , Li Aiyuan , Zeng Xianzhe , Guo Yitong , Zhao Yang , Chen Xiaolong , Meng Hong
Published: August 2018

Two new highly thermally stable [1]benzothieno[3,2‐b][1]benzothiophene (BTBT) dimeric derivatives, namely 1,4‐bis([1]benzothieno[3,2‐b][1]benzothiophene‐2‐yl)benzene (BTBT‐Ph‐BTBT) and 4,4′‐bis([1]benzothieno[3,2‐b][1]benzothiophene‐2‐yl)‐1,1′‐biphenyl (BTBT‐DPh‐BTBT), were synthesized by combining two simple fragment structures. Compared to the monomer compound 2‐phenyl[1]benzothieno[3,2‐b][1]benzothiophene (Ph‐BTBT, μmax=3.4×10−2 cm2 V−1 s−1), the organic thin‐film transistors (OTFTs) based on BTBT‐Ph‐BTBT and BTBT‐DPh‐BTBT showed significantly higher mobility (up to 2.5 and 3.6 cm2 V−1 s−1 for BTBT‐Ph‐BTBT and BTBT‐DPh‐BTBT, respectively). The mobility of OTFTs based on BTBT‐Ph‐BTBT was kept at a high value (2.4×10−1 cm2 V−1 s−1) after the devices were thermally annealed at 350 °C. Furthermore, the organic phototransistors (OPTs) based on BTBT‐Ph‐BTBT and BTBT‐DPh‐BTBT displayed high photosensitivities in a range of 250–400 nm with a low intensity, making these materials potentially applicable for sensitive optoelectronic devices.
Dispersive Forces and Dipole Moment Increase as Driving Forces for the Formation of an Unprecedented Metallophilic Heterotrimetallic System
Authors: Donamaría Rocío , Lippolis Vito , López‐de‐Luzuriaga José M. , Monge Miguel , Nieddu Mattia , Olmos M. Elena
Published: August 2018

The crystal structure of the polymeric complex [Au5Ag2Tl3(C6F5)10(L1)2]n (L1=1‐aza‐4,10‐dithia‐7‐oxacyclododecane) displays heterotrimetallic Ag⋅⋅⋅Au⋅⋅⋅Tl moieties and is held by unsupported metallophilic interactions. This complex emits at 500 nm in the solid state. Ab initio calculations show that the large thermodynamic stability that helps the formation of this heterotrimetallic system arises from the combination of dispersive forces and a very large dipole moment in the supramolecular arrangement.
Charge Accumulation and Multi‐Electron Photoredox Chemistry with a Sensitizer–Catalyst–Sensitizer Triad
Authors: Nomrowski Julia , Guo Xingwei , Wenger Oliver S.
Published: August 2018

Photoinduced electron transfer in donor–sensitizer–acceptor compounds usually leads to simple electron–hole pairs, and photoredox catalysis typically relies on single‐electron transfer (SET) events. This work reports on a molecular triad able to accumulate two electrons on a central dibenzo[1,2]dithiin moiety flanked by two peripheral RuII photosensitizers. Under continuous illumination, the doubly reduced form of the dibenzo[1,2]dithiin undergoes thiolate–disulfide exchange with an aliphatic disulfide substrate, thereby acting as a two‐electron catalyst after two initial SET events with triethylamine at the RuII sensitizers. The use of a relatively simple triad for coupling two separate SET processes to a subsequent two‐electron reduction is an important conceptual advance from photoinduced SET and light‐driven charge accumulation towards multi‐electron photoredox catalysis. This is relevant for artificial photosynthesis and light‐driven multi‐electron chemistry in general.