bluuebunny/crossref_metadata_2025_split huggingface dataset:
Superelastic and Arbitrary‐Shaped Graphene Aerogels with Sacrificial Skeleton of Melamine Foam for Varied Applications
Authors: Li Chenwei , Jiang Degang , Liang Hui , Huo Bingbing , Liu Chenyang , Yang Wenrong , Liu Jingquan 
Published: December 2017

AbstractElastic graphene aerogels are lightweight and offer excellent and electrical performance, expanding their significance in many applications. Recently, elastic graphene aerogels have been fabricated via various methods. However, for most reported elastic graphene aerogels, the fabrication processes are complicated and the applications are usually limited by the brittle mechanical properties. Thus, it still remains a challenge to explore facile processes for the fabrication of graphene aerogels with low density and high compressibility. Herein, arbitrary‐shaped, superelastic, and durable graphene aerogels are fabricated using melamine foam as sacrificial skeleton. The resulting graphene aerogels possess high elasticity under compressive stress of 0.556 MPa and compressive strain of 95%. Thanks to the superelasticity, high strength, excellent flexibility, outstanding thermal stability, and good electrical conductivity of graphene aerogels, they can be applied in sorbents and pressure/strain sensors. The as‐assembled graphene aerogels can adsorb various organic solvents at 176–513 g g−1 depending on the solvent type and density. Moreover, both the squeezing and combustion methods can be adopted for reusing the graphene aerogels. Finally, the graphene aerogels exhibit stable and sensitive current responses, making them the ideal candidates for applications as multifunctional pressure/strain sensors such as wearable devices.
Nature‐Inspired Metallic Networks for Transparent Electrodes
Authors: Gao Jinwei , Xian Zhike , Zhou Guofu , Liu Jun‐Ming , Kempa Krzysztof 
Published: December 2017

AbstractNature offers structural solutions to various optimization problems. For example, an optimal, low‐shedding water transport at various scales is achieved with quasi‐fractal structures, shown to be close to optimal. In a series of projects, metallic network analogs of some of these solutions to make high‐efficiency transparent conductors are studied. Specifically, transparent conductors are developed by directly metalizing leaf venations, spider webs, and other organic fibers. Also, the natural process of self‐cracking, similar to that occurring in the mud of dried‐out riverbeds, is employed to develop masks for metallic network fabrications. These comprehensive studies and developments contributed to, and in some cases initiate new directions in the field of network transparent conductors. These structures offer performance exceeding those of conventional oxide‐based films, while providing a possibility of reduced processing expense. This paper provides a concise, comparative review of this study and other groups' efforts in recent years. In the context of applications, the performance criteria are defined, and with those as a guideline, practicality of the most promising networks is discussed.
Facile Synthesis of Blocky SiOx/C with Graphite‐Like Structure for High‐Performance Lithium‐Ion Battery Anodes
Authors: Xu Quan , Sun Jian‐Kun , Yin Ya‐Xia , Guo Yu‐Guo 
Published: December 2017

AbstractSiOx‐containing graphite composites have aroused great interests as the most promising alternatives for practical application in high‐performance lithium‐ion batteries. However, limited loading amount of SiOx on the surface of graphite and some inherent disadvantages of SiOx such as huge volume variation and poor electronic conductivity result in unsatisfactory electrochemical performance. Herein, a novel and facile fabrication approach is developed to synthesize high‐performance SiOx/C composites with graphite‐like structure in which SiOx particles are dispersed and anchored in the carbon materials by restoring original structure of artificial graphite. The multicomponent carbon materials are favorable for addressing the disadvantages of SiOx‐based anodes, especially for the formation of stable solid electrolyte interphase, maintaining structural integrity of electrode materials and improving electrical conductivity of electrode. The resultant SiOx/C anodes demonstrate high reversible capacities (645 mA h g−1), excellent cycling stability (≈90% capacity retention for 500 cycles), and superior rate capabilities. Even at high pressing density (1.3 g cm−3), SiOx/C anodes still present superior cycling performance due to the high tap density and structural integrity of electrode materials. The proposed synthetic method can also be developed to address other anode materials with inferior electronic conductivity and huge volume variation.
Porphyrinic Metal–Organic Frameworks Coated Gold Nanorods as a Versatile Nanoplatform for Combined Photodynamic/Photothermal/Chemotherapy of Tumor
Authors: Zeng Jin‐Yue , Zhang Ming‐Kang , Peng Meng‐Yun , Gong Dan , Zhang Xian‐Zheng 
Published: December 2017

AbstractIn this paper, a simple, but effective method is reported to construct the core−shell gold nanorod@metal–organic frameworks (AuNR@MOFs) as a multifunctional theranostic platform by using functionalized AuNRs as seed crystal for the growth of porphyrinic MOFs on the surface of AuNR. Such a delicate tunable core−shell composite not only possesses the improved drug loading efficiency, near‐infrared light‐trigger drug release, and fluorescence imaging, but also can produce reactive oxygen species as well as photothermal activity to achieve combined cancer therapy. It is further demonstrated that the camptothecin loaded AuNR@MOFs show distinctively synergistic efficiency for damaging the cancer cell in vitro and inhibiting the tumor growth and metastasis in vivo. The development of this high‐performance incorporated nanostructure will provide more perspectives in the design of versatile nanomaterials for biomedical applications.
Rational Design of Tumor Microenvironment‐Activated Micelles for Programed Targeting of Breast Cancer Metastasis
Authors: He Bin , Tan Tao , Wang Hong , Hu Haiyan , Wang Zhiwan , Wang Jing , Li Jie , Sun Kaoxiang , Zhang Zhiwen , Li Yaping 
Published: December 2017

AbstractThe poor drug delivery to primary and metastatic tumors of breast cancer remains a great challenge for effective antimetastasis therapy. Herein, a tumor microenvironment‐activated cabazitaxel micelles decorated with legumain‐specific melittin (TCM‐legM) are rationally designed for programed targeting of breast cancer metastasis. TCM‐legM is quiescent in blood circulation, but can be specifically activated by the highly expressed legumain in tumor microenvironments to improve their specific targeting and deep penetrating to primary or metastatic tumors. Thereafter, the activated TCM‐legM can be efficiently internalized by cancer cells and motivate the rapid pH‐responsive drug release for antimetastasis therapy. In metastatic 4T1 breast cancer cells, TCM‐legM presents significant inhibition on the proliferation, migration, and invasion activities. In vivo, TCM‐legM can be effectively delivered to both primary and metastatic tumors of breast cancer with deep tumor penetration and efficient cellular internalization, thereby resulting in a notable reduction of tumor growth and producing a 93.4% suppression of lung metastasis. Taken together, the rationally designed TCM‐legM can provide an intelligent drug delivery strategy to enhance the medical performance on treating breast cancer metastasis.
Fully Printed Light‐Emitting Electrochemical Cells Utilizing Biocompatible Materials
Authors: Zimmermann Johannes , Porcarelli Luca , Rödlmeier Tobias , Sanchez‐Sanchez Ana , Mecerreyes David , Hernandez‐Sosa Gerardo 
Published: December 2017

AbstractThe use of biomaterials and bioinspired concepts in electronics will enable the fabrication of transient and disposable technologies within areas ranging from smart packaging and advertisement to healthcare applications. In this work, the use of a nonhalogenated biodegradable solid polymer electrolyte based on poly(ε‐caprolactone‐co‐trimethylene carbonate) and tetrabutylammonium bis‐oxalato borate in light‐emitting electrochemical cells (LECs) is presented. It is shown that the spin‐cast devices exhibit current efficiencies of ≈2 cd A−1 with luminance over ≈12 000 cd m−2, an order of magnitude higher than previous bio‐based LECs. By a combination of industrially relevant techniques (i.e., inkjet printing and blade coating), the fabrication of LEC devices on a cellulose‐based flexible biodegradable substrate showing lifetimes compatible with transient applications is demonstrated. The presented results have direct implications toward the industrial manufacturing of biomaterial‐based light‐emitting devices with potential use in future biodegradable/biocompatible electronics.
Influence of the Nature of A Cation on Dynamics of Charge Transfer Processes in Perovskite Solar Cells
Authors: Yadav Pankaj , Alotaibi Mohammad Hayal , Arora Neha , Dar M. Ibrahim , Zakeeruddin Shaik Mohammed , Grätzel Michael 
Published: December 2017

AbstractThe electronic processes occurring within the perovskite solar cells (PSCs) are strongly influenced by the nature of the organic A cations present within the inorganic framework. In this study, the impact of FA (CH(NH2)2+) and Cs+ cations on the intrinsic and interfacial properties in the FAPbBr3 and CsPbBr3 PSCs is investigated. The analysis of current density (JSC) and photovoltage (VOC) as a function of illumination intensity establishes that the interfacial charge transport is more rapid in FAPbBr3 devices. Small perturbation measurements including intensity modulated photocurrent and photovoltage spectroscopy are applied to explore the resistive and capacitive elements. Furthermore, electrochemical impedance spectroscopy measurements are found to correlate well with the photovoltaic characteristics of FAPbBr3 and CsPbBr3 PSCs. Overall, the in‐depth analysis of various phenomena occurring within the bromide PSCs allows to underline the working principle, which provides a key to optimize the device performance. The present protocol is not only valid for PSCs but can also be extended to devices based on alternative light harvesters.
Atomically Thin Mesoporous In2O3–x/In2S3 Lateral Heterostructures Enabling Robust Broadband‐Light Photo‐Electrochemical Water Splitting
Authors: Hou Jungang , Cao Shuyan , Sun Yiqing , Wu Yunzhen , Liang Fei , Lin Zheshuai , Sun Licheng 
Published: December 2017

AbstractAtomically thin 2D heterostructures have opened new realms in electronic and optoelectronic devices. Herein, 2D lateral heterostructures of mesoporous In2O3–x/In2S3 atomic layers are synthesized through the in situ oxidation of In2S3 atomic layers by an oxygen plasma‐induced strategy. Based on experimental observations and theoretical calculations, the prolonged charge carrier lifetime and increased electron density reveal the efficient photoexcited carrier transport and separation in the In2O3–x/In2S3 layers by interfacial bonding at the atomic level. As expected, the synergistic structural and electronic modulations of the In2O3–x/In2S3 layers generate a photocurrent of 1.28 mA cm−2 at 1.23 V versus a reversible hydrogen electrode, nearly 21 and 79 times higher than those of the In2S3 atomic layers and bulk counterpart, respectively. Due to the large surface area, abundant active sites, broadband‐light harvesting ability, and effective charge transport pathways, the In2O3–x/In2S3 layers build efficient pathways for photoexcited charge in the 2D semiconductive channels, expediting charge transport and kinetic processes and enhancing the robust broadband‐light photo‐electrochemical water splitting performance. This work paves new avenues for the exploration and design of atomically thin 2D lateral heterostructures toward robust photo‐electrochemical applications and solar energy utilization.
The influence of uncertainty on the choice of business relationships: The case of vegetable farmers in China
Authors: Li Lin , Guo Hongdong , Bijman Jos , Heerink Nico 
Published: December 2017

AbstractAlthough uncertainly is a common feature of agricultural markets, we know little about the effect of uncertainty on farmers’ choice of business relationships. This paper distinguishes production uncertainty, environmental uncertainty, and behavioral uncertainty in examining four kinds of business relationships of Chinese vegetable farmers: market exchange, cooperative membership without marketing transaction, cooperative membership with marketing transaction, and contract farming. We applied a multinomial logit model to data collected among 413 farmers in Hebei and Zhejiang provinces. The results suggested that all three types of uncertainty significantly affect the business relationships chosen by vegetable farmers. In particular, it was found that as production uncertainty increases, farmers prefer contract farming and both cooperative membership with and without marketing transaction over market exchange; while as behavioral uncertainty increases, farmers are less likely to be involved in contract farming. Environmental uncertainty does not affect the likelihood that farmers choose market exchange or contract farming, while mixed results are obtained for its effects on cooperative membership with and without marketing transaction. [EconLit citations: L140; Q130].
A quantitative approach for sex estimation based on cranial morphology
Authors: Nikita Efthymia , Michopoulou Efrossyni 
Published: December 2017

AbstractObjectivesThis paper proposes a method for the quantification of the shape of sexually dimorphic cranial traits, namely the glabella, mastoid process and external occipital protuberance.Materials and methodsThe proposed method was developed using 165 crania from the documented Athens Collection and tested on 20 Cretan crania. It is based on digital photographs of the lateral view of the cranium, drawing of the profile of three sexually dimorphic structures and calculation of variables that express the shape of these structures.ResultsThe combinations of variables that provide optimum discrimination between sexes are identified by means of binary logistic regression and discriminant analysis. The best cross‐validated results are obtained when variables from all three structures are combined and range from 75.8 to 85.1% and 81.1 to 94.6% for males and females, respectively. The success rate is 86.3–94.1% for males and 83.9–93.5% for females when half of the sample is used for training and the rest for prediction. Correct classification for the Cretan material based upon the standards developed for the Athens sample was 80–90% for the optimum combinations of discriminant variables.DiscussionThe proposed method provides an effective way to capture quantitatively the shape of sexually dimorphic cranial structures; it gives more accurate results relative to other existing methods and it does not require specialized equipment. Equations for sex estimation based on combinations of variables are provided, along with instructions on how to use the method and Excel macros for calculation of discriminant variables with automated implementation of the optimum equations.
Reconstitution of a Type II Polyketide Synthase that Catalyzes Polyene Formation
Authors: Du Danyao , Katsuyama Yohei , Shin‐ya Kazuo , Ohnishi Yasuo 
Published: December 2017

AbstractWhile type II polyketide synthases (PKSs) are known for producing aromatic compounds, a phylogenetically new subfamily of type II PKSs have been recently proposed to synthesize polyene structures. Here we report in vitro analysis of such a type II PKS, IgaPKS for ishigamide biosynthesis. The ketoreductase (Iga13) and dehydratase (Iga16) were shown to catalyze the reduction of a β‐keto group and dehydration of a β‐hydroxy group, respectively, to form a trans double bond. Incubation of the acyl carrier protein (Iga10), the ketosynthase/chain length factor complex (Iga11–Iga12), Iga13 and Iga16 with malonyl and hexanoyl‐CoAs and NADPH followed by KOH hydrolysis resulted in the formation of four unsaturated carboxylic acids (C8, C10, C12, and C14), indicating that IgaPKS catalyzes tetraene formation by repeating the cycle of condensation, keto‐reduction and dehydration with strict stereo‐specificity. We propose “highly reducing type II PKS subfamily” for the polyene‐producing type II PKSs.
Highly Regio‐ and Stereodivergent Access to 1,2‐Amino Alcohols or 1,4‐Fluoro Alcohols by NHC‐Catalyzed Ring Opening of Epoxy enals
Authors: Poh Si Bei , Ong Jun‐Yang , Lu Shenci , Zhao Yu 
Published: December 2017

AbstractDescribed is an unprecedented NHC‐catalyzed (NHC=N‐heterocyclic carbene), stereoselective ring opening of epoxy and cyclopropyl enals to deliver valuable compounds bearing multiple stereocenters. A straightforward three‐step procedure involving two catalytic enantioselective transformations has been developed and leads to a regio‐ and stereodivergent synthesis of either 1,2‐amino alcohols/diamines or 1,4‐fluoro alcohols with excellent diastereo‐ and enantiopurity.
In‐Plane Black Phosphorus/Dicobalt Phosphide Heterostructure for Efficient Electrocatalysis
Authors: Wang Jiahong , Liu Danni , Huang Hao , Yang Na , Yu Bo , Wen Min , Wang Xin , Chu Paul K. , Yu Xue‐Feng 
Published: December 2017

AbstractHeterostructures composed of two‐dimensional black phosphorus (2D BP) with unique physical/chemical properties are of great interest. Herein, we report a simple solvothermal method to synthesize in‐plane BP/Co2P heterostructures for electrocatalysis. By using the reactive edge defects of the BP nanosheets as the initial sites, Co2P nanocrystals are selectively grown on the BP edges to form the in‐plane BP/Co2P heterostructures. Owing to disposition on the original defects of BP, Co2P improves the conductivity and offers more active electrocatalytic sites, so that the BP/Co2P nanosheets exhibit better and more stable electrocatalytic activities in the hydrogen evolution and oxygen evolution reactions. Our work not only extends the application of BP to electrochemistry, but also provides a new idea to improve the performance of BP by utilization of defects. Furthermore, this strategy can be extended to produce other BP heterostructures to expand the corresponding applications.
Auf sichtbares Licht ansprechende Photoanoden für hochaktive, dauerhafte Wasseroxidation
Authors: Seo Jeongsuk , Nishiyama Hiroshi , Yamada Taro , Domen Kazunari 
Published: December 2017

AbstractSolarenergie ist eine natürliche und ständig verfügbare Ressource, sodass die Umwandlung von Sonnenstrahlung in chemische oder elektrische Energie eine attraktive Möglichkeit, wenngleich auch eine anspruchsvolle Herausforderung, darstellt. Die photoelektrochemische (PEC‐)Wasserspaltung spielt eine Schlüsselrolle bei der Herstellung von Wasserstoff aus Solarenergie als Energiequelle der Zukunft. Allerdings ist die praktische Wasseroxidation an Photoanoden (in Kombination mit der Wasserreduktion an einer Photokathode) für PEC‐Zellen aufgrund hoher Überspannungen und geringer Photoaktivität der Halbleiter derzeit nur schwer realisierbar. Für eine effiziente und dauerhafte Wasseroxidation wird die Entwicklung von Halbleitern notwendig sein, die hohe Wirkungsgrade bei der Umwandlung von Solarenergie in Wasserstoff ermöglichen und in Photoanoden nutzbar sind. In diesem Aufsatz werden Fortschritte in der Wasseroxidationsaktivität von Photoanoden aus (Oxy)Nitriden und Oxiden vom n‐Typ beschrieben.
Direkte Umwandlung von Estern in heterocyclische Fluorophore
Authors: Fischer Christian , Sparr Christof 
Published: December 2017

AbstractObwohl heterocyclische Fluorophore vielseitig eingesetzt werden, kann mit den derzeitigen Synthesemethoden nur ein Bruchteil der erwünschten Farbstoffdiversität zugänglich gemacht werden. Hier beschreiben wir eine modulare Methode, welche verschiedenste Carbonsäureester direkt in ein breites Spektrum an Heteroanthrylium‐Fluorophore umwandelt. Die doppelte Addition von Heteroatom‐verknüpften 1,5‐difunktionellen Organomagnesium‐Reagenzien an Ester führt nach dehydratisierender saurer Aufarbeitung zur Bildung von Acridinium‐, Xanthylium‐ und SiR‐Fluorophoren. Diese einstufige Synthesemethode liefert organische Photoredoxkatalysatoren für die duale Katalyse mit Nickel und Fluorophore, welche Fluoreszenzverstärkungsreaktionen zulassen.
Pd‐Catalyzed Enantioselective [6+4] Cycloaddition of Vinyl Oxetanes with Azadienes to Access Ten‐Membered Heterocycles
Authors: Wang Ya‐Nong , Yang Li‐Cheng , Rong Zi‐Qiang , Liu Tang‐Lin , Liu Ruoyang , Zhao Yu 
Published: December 2017

AbstractWe report herein the first enantioselective cycloaddition of vinyl oxetanes, the reaction of which with azadienes provided unprecedented access to ten‐membered heterocycles through a [6+4] cycloaddition. By using a commercially available chiral Pd‐SIPHOX catalyst, a wide range of benzofuran‐ as well as indole‐fused heterocycles could be accessed in excellent yield and enantioselectivity. A unique Lewis acid induced fragmentation of these ten‐membered heterocycles was also discovered.
Direct Transformation of Esters into Heterocyclic Fluorophores
Authors: Fischer Christian , Sparr Christof 
Published: December 2017

AbstractDespite the manifold use of heterocyclic fluorophores, only a fraction of the desired dye diversity can be accessed by contemporary synthetic approaches. Herein, we describe a modular method that converts various carboxylic acid esters directly into a broad spectrum of heteroanthrylium fluorophores. The double addition of heteroatom‐bridged 1,5‐bifunctional organomagnesium reagents to esters leads to the formation of acridinium, xanthylium, and SiR fluorophores after dehydrative acidic work‐up. This one‐step synthetic method provides access to organophotoredox catalysts for dual catalysis with nickel and dyes amenable to fluorescence enhancement.
Can satellite ponds buffer the impact of introduced fish on newts in a mountain pond network?
Authors: Tiberti Rocco 
Published: December 2017

Abstract

Fish introductions into originally fishless mountain lentic habitats can affect native amphibians at different spatial scales. Introductions are often associated with local extinctions, but they can also affect amphibian metapopulations at a landscape level, intercepting amphibians when they move into reproductive and overwintering sites, preventing these movements, or reducing the overall metapopulation abundance and diversity.
Freshwater habitat networks are considered more resistant to biological invasions than isolated habitats, because they usually provide safe alternative sites that can buffer the impact of introduced fish. However, few studies have attempted to understand whether fish stocking also affects amphibians in surrounding fishless habitats.
This general hypothesis was tested using distribution data of Italian crested newt (Triturus carnifex Laurenti 1768) in a mountain pond network collected over a 13‐year‐long study (2005–2017), encompassing the periods before (pre‐2011) and after (post‐2012) fish (Salmo trutta L. 1758) were introduced in the pond where most of the newts were initially observed.
After fish introduction, visual counts dropped down close to zero in the invaded pond, but they increased in satellite ponds. This was a progressive increase not related to population size and should be regarded as a short‐term consequence of the slow colonization of satellite ponds.
These results confirm the dramatic impact of fish introductions on native amphibians at a local scale, but suggest that some amphibians can counteract their impact by moving to alternative sites, when available.
Halting fish stocking, lake and pond recovery, and the construction of alternative sites are proposed as management and conservation actions to preserve amphibian diversity.