bluuebunny/crossref_metadata_2025 huggingface dataset:
Conjugated Polymer Nanoparticles toward In Vivo Theranostics – Focus on Targeting, Imaging, Therapy, and the Importance of Clearance
Authors: Kuehne Alexander J. C.
Published: August 2017

Conjugated polymer nanoparticles are highly fluorescent colloids with tunable emission colors ranging from the visible deep into the near infrared spectrum. Conjugated polymer nanoparticles are easy to prepare, tunable in their size, and virtually nonbleachable. Conjugated polymer particles can also be designed to give off heat upon irradiation. All these properties make conjugated polymer particles ideal materials for biomedical fluorescence and photoacoustic imaging as well as for theranostic applications. Here, different examples of surface functionalization to attach pathological homing devices, imaging modalities, as well as the emerging possibilities for therapeutic measures are discussed. Furthermore, clearance of the particles is considered, which is important to ultimately apply the materials for in vivo theranostics. Due to the conjugated backbone of the conjugated polymers, established degradation strategies, as known from hydrophilic nonconjugated polymer carriers, cannot be applied. Bioinspired strategies and potential pathways for degradation and clearance via structural changes upon triggers such as pH, oxidation, and temperature are also discussed in this progress report.
Temperature Effect on Performance of Triboelectric Nanogenerator
Authors: Lu Cun Xin , Han Chang Bao , Gu Guang Qin , Chen Jian , Yang Zhi Wei , Jiang Tao , He Chuan , Wang Zhong Lin
Published: August 2017

The triboelectric nanogenerator (TENG) is a promising energy harvesting technology that can convert mechanical energy into electricity and can be used as self‐powered active sensors. However, previous studies are mostly carried out at room temperature without considering the temperature effect on the electrical performance of TENGs, which is critical for the application of electronics powered by TENGs in different regions in the world. In the present work, a TENG that worked in the single‐electrode and contact‐separation mode is utilized to reveal the influence of environment temperature on the electrical performance of TENG. The electrical performance of the TENG shows a decreasing tendency, as the temperature rises from −20 to 150 °C, which is controlled by the temperature‐induced changes in the ability of storing and gaining electrons for polytetrafluoroethylene (PTFE). The storing electron ability change of PTFE is attributed to two aspects: one is the reduction of relative permittivity of PTFE sheet as the temperature increases, and the other is the variations of effective defects such as the escape of trapped charges in shallow traps and surface oxidation under the effect of temperature perturbation. This work can provide useful information for the application of TENG in both electric power generation and self‐powered sensors in the harsh environment.
Black Phosphorus Nanoparticles Potentiate the Anticancer Effect of Oxaliplatin in Ovarian Cancer Cell Line
Authors: Fojtů Michaela , Chia Xinyi , Sofer Zdeněk , Masařík Michal , Pumera Martin
Published: August 2017

During the past few years, growing attention has been paid to black phosphorus (BP) and its unique optical, electrical, and catalytic properties. Furthermore, BP has proven to be biocompatible and biodegradable; qualities that present new opportunities for its utilization in the field of life sciences. However, despite all its suitable properties and applicability, its utilization in biomedicine is still in its infancy. This study reports on the synthesis of black phosphorus nanoparticles (BP NPs) and exploration of thier applicability in targeted drug delivery. BP NPs are loaded with platinum agents—cisplatin and oxaliplatin—and subjected to in vitro evaluation of targeted drug delivery. The BP NPs are not only able to load the investigated platinum derivatives on their surfaces, but also to transfer the therapeutic cargo to target specific tissue and to combine their effect with oxaliplatin, which leads to further potentiation of the anticancer effect.
General Synthesis of Dual Carbon‐Confined Metal Sulfides Quantum Dots Toward High‐Performance Anodes for Sodium‐Ion Batteries
Authors: Chen Ziliang , Wu Renbing , Liu Miao , Wang Hao , Xu Hongbin , Guo Yanhui , Song Yun , Fang Fang , Yu Xuebin , Sun Dalin
Published: August 2017

Sponge‐like composites assembled by cobalt sulfides quantum dots (Co9S8 QD), mesoporous hollow carbon polyhedral (HCP) matrix, and a reduced graphene oxide (rGO) wrapping sheets are synthesized by a simultaneous thermal reduction, carbonization, and sulfidation of zeolitic imidazolate frameworks@GO precursors. Specifically, Co9S8 QD with size less than 4 nm are homogenously embedded within HCP matrix, which is encapsulated in macroporous rGO, thereby leading to the double carbon‐confined hierarchical composites with strong coupling effect. Experimental data combined with density functional theory calculations reveal that the presence of coupled rGO not only prevents the aggregation and excessive growth of particles, but also expands the lattice parameters of Co9S8 crystals, enhancing the reactivity for sodium storage. Benefiting from the hierarchical porosity, conductive network, structural integrity, and a synergistic effect of the components, the sponge‐like composites used as binder‐free anodes manifest outstanding sodium‐storage performance in terms of excellent stable capacity (628 mAh g−1 after 500 cycles at 300 mA g−1) and exceptional rate capability (529, 448, and 330 mAh g−1 at 1600, 3200, and 6400 mA g−1). More importantly, the synthetic method is very versatile and can be easily extended to fabricate other transition‐metal‐sulfides‐based sponge‐like composites with excellent electrochemical performances.
Shape‐Reconfigurable Aluminum–Air Batteries
Authors: Choi Sangjin , Lee Daehee , Kim Gwangmook , Lee Yoon Yun , Kim Bokyung , Moon Jooho , Shim Wooyoung
Published: August 2017

The battery shape is a critical limiting factor affecting foreseeable energy storage applications. In particular, deformable metal–air battery systems can offer low cost, low flammability, and high capacity, but the fabrication of such metal–air batteries remains challenging. Here, it is shown that a shape‐reconfigurable‐material approach, in which the deformable components composed of micro‐ and nanoscale composites are assembled, is suitable for constructing polymorphic metal–air batteries. By employing an aluminum foil and an adhesive carbon composite placed on a cellulose scaffold as a substrate, an aluminum–air battery that can be deformed to an unprecedented high level, e.g., via expanding, folding, stacking, and crumpling, can be realized. This significant deformability results in a specific capacity of 128 mA h g−1 (496 mA h g−1 per cell; based on the mass of consumed aluminum) and a high output voltage (10.3 V) with 16 unit battery cells connected in series. The resulting battery can endure significant geometrical distortions such as 3D expanding and twisting, while the electrochemical performance is preserved. This work represents an advancement in deformable aluminum–air batteries using the shape‐reconfigurable‐material concept, thus establishing a paradigm for shape‐reconfigurable batteries with exceptional mechanical functionalities.
Rationally Designed Donor–Acceptor Random Copolymers with Optimized Complementary Light Absorption for Highly Efficient All‐Polymer Solar Cells
Authors: Kim Sang Woo , Choi Joonhyeong , Bui Thi Thu Trang , Lee Changyeon , Cho Changsoon , Na Kwangmin , Jung Jihye , Song Chang Eun , Ma Biwu , Lee Jung‐Yong , Shin Won Suk , Kim Bumjoon J.
Published: August 2017

Most of the high‐performance all‐polymer solar cells (all‐PSCs) reported to date are based on polymer donor and polymer acceptor pairs with largely overlapped light absorption properties, which seriously limits the efficiency of all‐PSCs. This study reports the development of a series of random copolymer donors possessing complementary light absorption with the naphthalenediimide‐based polymer acceptor P(NDI2HD‐T2) for highly efficient all‐PSCs. By controlling the molar ratio of the electron‐rich benzodithiophene (BDTT) and electron‐deficient fluorinated‐thienothiophene (TT‐F) units, a series of polymer donors with BDTT:TT‐F ratios of 1:1 (P1), 3:1 (P2), 5:1 (P3), and 7:1 (P4) are prepared. The synthetic control of polymer composition allows for precise tuning of the light absorption properties of these new polymer donors, enabling optimization of light absorption properties to complement those of the P(NDI2HD‐T2) acceptor. Copolymer P1 is found to be the optimal polymer donor for the fullerene‐based solar cells due to its high light absorption, whereas the highest power conversion efficiency of 6.81% is achieved for the all‐PSCs with P3, which has the most complementary light absorption with P(NDI2HD‐T2).
Integrin‐Mediated Interactions Control Macrophage Polarization in 3D Hydrogels
Authors: Cha Byung‐Hyun , Shin Su Ryon , Leijten Jeroen , Li Yi‐Chen , Singh Sonali , Liu Julie C. , Annabi Nasim , Abdi Reza , Dokmeci Mehmet R. , Vrana Nihal Engin , Ghaemmaghami Amir M. , Khademhosseini Ali
Published: August 2017

Adverse immune reactions prevent clinical translation of numerous implantable devices and materials. Although inflammation is an essential part of tissue regeneration, chronic inflammation ultimately leads to implant failure. In particular, macrophage polarity steers the microenvironment toward inflammation or wound healing via the induction of M1 and M2 macrophages, respectively. Here, this paper demonstrates that macrophage polarity within biomaterials can be controlled through integrin‐mediated interactions between human monocytic THP‐1 cells and collagen‐derived matrix. Surface marker, gene expression, biochemical, and cytokine profiling consistently indicate that THP‐1 cells within a biomaterial lacking cell attachment motifs yield proinflammatory M1 macrophages, whereas biomaterials with attachment sites in the presence of interleukin‐4 (IL‐4) induce an anti‐inflammatory M2‐like phenotype and propagate the effect of IL‐4 in induction of M2‐like macrophages. Importantly, integrin α2β1 plays a pivotal role as its inhibition blocks the induction of M2 macrophages. The influence of the microenvironment of the biomaterial over macrophage polarity is further confirmed by its ability to modulate the effect of IL‐4 and lipopolysaccharide, which are potent inducers of M2 or M1 phenotypes, respectively. Thus, this study represents a novel, versatile, and effective strategy to steer macrophage polarity through integrin‐mediated 3D microenvironment for biomaterial‐based programming.
Human Perinatal‐Derived Biomaterials
Authors: Moore Marc C. , Van De Walle Aurore , Chang Jerry , Juran Cassandra , McFetridge Peter S.
Published: August 2017

Human perinatal tissues have been used for over a century as allogeneic biomaterials. Due to their advantageous properties including angiogenecity, anti‐inflammation, anti‐microbial, and immune privilege, these tissues are being utilized for novel applications across wide‐ranging medical disciplines. Given continued clinical success, increased adoption of perinatal tissues as a disruptive technology platform has allowed for significant penetration into the multi‐billion dollar biologics market. Here, we review current progress and future applications of perinatal biomaterials, as well as associated regulatory issues.
Introduction of Red‐Green‐Blue Fluorescent Dyes into a Metal–Organic Framework for Tunable White Light Emission
Authors: Wen Yuehong , Sheng Tianlu , Zhu Xiaoquan , Zhuo Chao , Su Shaodong , Li Haoran , Hu Shengmin , Zhu Qi‐Long , Wu Xintao
Published: August 2017

The unique features of the metal–organic frameworks (MOFs), including ultrahigh porosities and surface areas, tunable pores, endow the MOFs with special utilizations as host matrices. In this work, various neutral and ionic guest dye molecules, such as fluorescent brighteners, coumarin derivatives, 4‐(dicyanomethylene)‐2‐methyl‐6‐(p‐dimethylaminostyryl)‐4H‐pyran (DCM), and 4‐(p‐dimethylaminostyryl)‐1‐methylpyridinium (DSM), are encapsulated in a neutral MOF, yielding novel blue‐, green‐, and red‐phosphors, respectively. Furthermore, this study introduces the red‐, green‐, and blue‐emitting dyes into a MOF together for the first time, producing white‐light materials with nearly ideal Commission International ed'Eclairage (CIE) coordinates, high color‐rendering index values (up to 92%) and quantum yields (up to 26%), and moderate correlated color temperature values. The white light is tunable by changing the content or type of the three dye guests, or the excitation wavelength. Significantly, the introduction of blue‐emitting guests in the methodology makes the available MOF host more extensive, and the final white‐light output more tunable and high‐quality. Such strategy can be widely adopted to design and prepare white‐light‐emitting materials.
Thermal Exfoliation of Layered Metal–Organic Frameworks into Ultrahydrophilic Graphene Stacks and Their Applications in Li–S Batteries
Authors: Hao Guang‐Ping , Tang Cheng , Zhang En , Zhai Peiyan , Yin Jun , Zhu Wancheng , Zhang Qiang , Kaskel Stefan
Published: August 2017

2D nanocarbon‐based materials with controllable pore structures and hydrophilic surface show great potential in electrochemical energy storage systems including lithium sulfur (Li–S) batteries. This paper reports a thermal exfoliation of metal–organic framework crystals with intrinsic 2D structure into multilayer graphene stacks. This family of nanocarbon stacks is composed of well‐preserved 2D sheets with highly accessible interlayer macropores, narrowly distributed 7 Å micropores, and ever most polar pore walls. The surface polarity is quantified both by its ultrahigh water vapor uptake of 14.3 mmol g−1 at low relative pressure of P/P0 = 0.4 and ultrafast water wetting capability in less than 10.0 s. Based on the structural merits, this series hydrophilic multilayer graphene stack is showcased as suitable model cathode host for unveiling the challenging surface chemistry issue in Li–S batteries.
Sensitive, Quantitative Naked‐Eye Biodetection with Polyhedral Cu Nanoshells
Authors: Kim Jae‐Ho , Park Jeong‐Eun , Lin Mouhong , Kim Sungi , Kim Gyeong‐Hwan , Park SungJun , Ko GwangPyo , Nam Jwa‐Min
Published: August 2017

One of the most heavily used methods in chemical and biological labeling, detection, and imaging is based on silver shell‐based enhancement on Au nanoparticles (AuNPs) that is useful for amplifying Rayleigh scattering, colorimetric signal, surface‐enhanced Raman scattering, and electrical signal, but poor structural controllability and nonspecific growth of silver shells have limited its applications, especially with respect to signal reproducibility and quantification. Here, a highly specific, well‐defined Cu nanopolyhedral shell overgrowth chemistry is developed with the aid of polyethyleneimine (PEI) on AuNPs, and the use of this PEI‐mediated Cu polyhedral nanoshell (CuP) chemistry is shown as a means of light‐scattering signal enhancement for the development of naked‐eye‐based highly sensitive and quantitative detections of DNA and viruses. Remarkably, these CuPs are exclusively formed on AuNPs in a controllable manner, with no noticeable nonspecific CuP growth. The findings enable to acquire clearly visible signals without analytic instrumentation, detectable down to 8 × 10−15m of DNA (anthrax sequence) and 2700 copies of viruses (noroviruses in clinical stool samples) with broad dynamic ranges on archetypal assay platforms. This new method provides a general platform in controlling Cu shell nanostructures and their optical signals, and opens up revenues for highly reliable, quantitative onsite naked‐eye biodetection.
Surfaces Inspired by the Nepenthes Peristome for Unidirectional Liquid Transport
Authors: Zhang Pengfei , Zhang Liwen , Chen Huawei , Dong Zhichao , Zhang Deyuan
Published: August 2017

The slippery peristome of the pitcher plant Nepenthes has attracted much attention due to its unique function for preying on insects. Recent findings on the peristome surface of Nepenthes alata demonstrate a fast and continuous unidirectional liquid transport, which is enabled by the combination of a pinning effect at the sharp edges and a capillary rise in the wedge, deriving from the multiscale structure, which provides inspiration for designing and fabricating functional surfaces for unidirectional liquid transport. Developments in the fabrication methods of peristome‐inspired surfaces and control methods for liquid transport are summarized. Both potential applications in the fields of microfluidic devices, biomedicine, and mechanical engineering and directions for further research in the future are discussed.
Mixed Ionic–Electronic Conduction in Binary Polymer Nanoparticle Assemblies
Authors: Renna Lawrence A. , Lenef Julia D. , Bag Monojit , Venkataraman D.
Published: August 2017

Polymer‐based mixed ionic–electronic conductors (MIECs) are desired for both bulk and interfacial materials in next‐generation energy storage and electronic devices. Polymer‐based MIECs contain two principal components, one for electronic conduction and the other for ionic conduction. The central problem is the lack of a general approach to control the molecular packing and morphology of the constituent components that will afford the ability to easily tune transport properties. This study demonstrates the efficacy of a modular method based on polymer nanoparticle self‐assembly to achieve MIECs with tunable conductivity. This work uses poly(3‐hexylthiophene) nanoparticles as the electronic conductor and lithium ion‐doped poly(vinylpyridine) nanoparticles as the ionic conductors. AC impedance spectroscopic studies show that nanoparticle–nanoparticle interfaces in unary assemblies do not impede ion transport in the solid state. AC impedance spectroscopy and DC steady‐state conductivity measurements show that binary nanoparticle assemblies exhibit concurrent ionic and electronic conduction. The power‐law scaling percolation of both the ionic and electronic transport displays nonuniversal values of transport critical exponent, revealing different transport mechanisms. The simplicity of fabrication combined with the versatility in obtainable transport properties illustrates the power of using nanoparticle assemblies as a means to realize MIEC polymer mesoscale morphologies.
Vastly Enhanced BiVO4 Photocatalytic OER Performance by NiCoO2 as Cocatalyst
Authors: Palaniselvam Thangavelu , Shi Le , Mettela Gangaiah , Anjum Dalavar H. , Li Renyan , Katuri Krishna P. , Saikaly Pascal E. , Wang Peng
Published: August 2017

Here, a simple and efficient preparation of NiCoO2 nanoparticle modified nanoporous bismuth vanadate (BiVO4) thin film and its application in photoelectrocatalytic (PEC) oxygen evolution reaction (OER) is demonstrated. The role of NiCoO2 in the composite electrode (BiVO4/NiCoO2) is twofold: OER cocatalyst and band structure modifier. It improves surface reaction kinetics for PEC OER and enhances charge separation efficiency simultaneously, which is believed to be a determining factor for the unprecedentedly high PEC OER performance of this BiVO4/NiCoO2 nanocomposite. The photocurrent density of 3.6 mA cm−2 at 1.23 V versus RHE in 0.1 m potassium phosphate buffered (pH = 7) electrolyte by BiVO4/NiCoO2 is three times that of BiVO4 and significantly higher than most literature values. The BiVO4/NiCoO2 nanocomposite shows/possess a high charge separation efficiency (ηsurface) of ≈72% as compared to only 23% for pure nanoporous BiVO4 at 1.23 V versus RHE, which demonstrates convincing role of NiCoO2 in the composite electrode. Both the excellent photocurrent density and great operational stability of this BiVO4/NiCoO2 nanocomposite makes it a promising photocatalytic material for practical applications.
Two‐Step Synthesis of Polysubstituted 6‐Nitroindoles under Flow Chemical and Microwave Conditions
Authors: Sampaolesi Susanna , Gabrielli Serena , Ballini Roberto , Palmieri Alessandro
Published: August 2017

A new simple and efficient synthesis of 6‐nitroindoles, starting from N‐carboxylalkylpyrrole‐2‐carboxaldehydes and protected β‐nitro ketones, has been developed. The method involves two distinct domino processes, respectively performed under flow chemical conditions and microwave irradiation. 6‐Nitroindoles were produced in good to excellent overall yields.

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Recent Advances in Understanding the Structure and Properties of Amorphous Oxide Semiconductors
Authors: Medvedeva Julia E. , Buchholz D. Bruce , Chang Robert P. H.
Published: August 2017

Amorphous oxide semiconductors (AOSs)—ternary or quaternary oxides of post‐transition metals such as In‐Sn‐O, Zn‐Sn‐O, or In‐Ga‐Zn‐O—have been known for a decade and have attracted a great deal of attention as they possess several technological advantages, including low‐temperature large‐area deposition, mechanical flexibility, smooth surfaces, and high carrier mobility that is an order of magnitude larger than that of amorphous silicon (a‐Si:H). Compared to their crystalline counterparts, the structure of AOSs is extremely sensitive to deposition conditions, stoichiometry, and composition, giving rise to a wide range of tunable optical and electrical properties. The large parameter space and the resulting complex deposition–structure–property relationships in AOSs make the currently available theoretical and experimental research data rather scattered and the design of new materials difficult. In this work, the key properties of several In‐based AOSs are studied as a function of cooling rates, oxygen stoichiometry, cation composition, or lattice strain. Based on a thorough comparison of the results of ab initio modeling, comprehensive structural analysis, accurate property calculations, and systematic experimental measurements, a four‐dimensional parameter space for AOSs is derived, serving as a solid foundation for property optimization in known AOSs and for design of next‐generation transparent amorphous semiconductors.
Steric‐Hindrance Modulation toward High‐Performance 1,3‐Bis(thieno[3,4‐b]thiophen‐6‐yl)‐4H‐thieno[3,4‐c]pyrrole‐4,6(5H)‐dione‐Based Polymer Solar Cells with Enhanced Open‐Circuit Voltage
Authors: Zhang Cheng , Zhou Zichun , Wu Hao , Liu Feng , Zhu Xiaozhang
Published: August 2017

Solution‐processed bulk‐heterojunction polymer solar cells (PSCs) are indispensable in photovoltaics. π‐Conjugated donor–acceptor copolymers as electron donors have become the cornerstone as the most intensively studied topic in this field. Thieno[3,4‐c]pyrrole‐4,6‐dione (TPD) is one of the most commonly used electron‐withdrawing moieties. Based on TPD, a new building block, 1,3‐bis(thieno[3,4‐b]thiophen‐6‐yl)‐4H‐thieno[3,4‐c]pyrrole‐4,6(5H)‐dione (TBTT), is designed and a novel low‐bandgap TPD‐copolymer is developed with a power conversion efficiency (PCE) up to 7.5% with a low open‐circuit voltage (Voc) of 0.633 V when utilizing PC71BM as electron acceptor. To promote the performance of TBTT‐based polymers, four conjugated copolymers are designed and synthesized based on TBTT and benzodithiophene (BDT) building blocks by regulating their steric hindrance with side alkyl chains on BDT moiety. PSCs based on polymer P4 with an additional n‐hexyl side chain blended with PC71BM deliver a high PCE of 9.1% with a Voc of 0.78 V increased by 24%, which is among the highest in TPD‐based polymers. The study provides new insights into the molecular design and synthesis of high‐performance photovoltaic materials.
Triboelectrification‐Enabled Self‐Charging Lithium‐Ion Batteries
Authors: Zhao Kun , Yang Ya , Liu Xi , Wang Zhong Lin
Published: August 2017

Li‐ion batteries as energy storage devices need to be periodically charged for sustainably powering electronic devices owing to their limited capacities. Here, the feasibility of utilizing Li‐ion batteries as both the energy storage and scavenging units is demonstrated. Flexible Li‐ion batteries fabricated from electrospun LiMn2O4 nanowires as cathode and carbon nanowires as anode enable a capacity retention of 90% coulombic efficiency after 50 cycles. Through the coupling between triboelectrification and electrostatic induction, the adjacent electrodes of two Li‐ion batteries can deliver an output peak voltage of about 200 V and an output peak current of about 25 µA under ambient wind‐induced vibrations of a hexafluoropropene–tetrafluoroethylene copolymer film between the two Li‐ion batteries. The self‐charging Li‐ion batteries have been demonstrated to charge themselves up to 3.5 V in about 3 min under wind‐induced mechanical excitations. The advantages of the self‐charging Li‐ion batteries can provide important applications for sustainably powering electronics and self‐powered sensor systems.
A Multisite Strategy for Enhancing the Hydrogen Evolution Reaction on a Nano‐Pd Surface in Alkaline Media
Authors: Liao Hanbin , Wei Chao , Wang Jingxian , Fisher Adrian , Sritharan Thirumany , Feng Zhenxing , Xu Zhichuan J.
Published: August 2017

The hydrogen evolution reaction (HER) on a noble metal surface in alkaline media is more sluggish than that in acidic media due to the limited proton supply. To promote the reaction, it is necessary to transform the alkaline HER mechanism via a multisite catalyst, which has additional water dissociation sites to improve the proton supply to an optimal level. Here, this study reports a top‐down strategy to create a multisite HER catalyst on a nano‐Pd surface and how to further fine‐tune the areal ratio of the water dissociation component to the noble metal surface in core/shell‐structured nanoparticles (NPs). Starting with Pd/Fe3O4 core/shell NPs, electrochemical cycling is used to tune the coverage of iron (oxy)hydroxide on a Pd surface. The alkaline HER activity of the core/sell Pd/FeOx(OH)2−2x NPs exhibits a volcano‐shaped correlation with the surface Fe species coverage. This indicates an optimum coverage level where the rates of both the water dissociation step and the hydrogen formation step are balanced to achieve the highest efficiency. This multisite strategy assigns multiple reaction steps to different catalytic sites, and should also be extendable to other core/shell NPs to optimize their HER activity in alkaline media.
Optimized Bicompartment Two Solution Cells for Effective and Stable Operation of Li–O2 Batteries
Authors: Kwak Won‐Jin , Jung Hun‐Gi , Aurbach Doron , Sun Yang‐Kook
Published: August 2017

Lithium–oxygen batteries are in fact the only rechargeable batteries that can rival internal combustion engines, in terms of high energy density. However, they are still under development due to low‐efficiency and short lifetime issues. There are problems of side reactions on the cathode side, high reactivity of the Li anode with solution species, and consumption of redox mediators via reactions with metallic lithium. Therefore, efforts are made to protect/block the lithium metal anode in these cells, in order to mitigate side reactions. However, new approach is required in order to solve the problems mentioned above, especially the irreversible reactions of the redox mediators which are mandatory to these systems with the Li anode. Here, optimized bicompartment two solution cells are proposed, in which detrimental crossover between the cathode and anode is completely avoided. The Li metal anode is cycled in electrolyte solution containing fluorinated ethylene carbonate, in which its cycling efficiency is excellent. The cathode compartment contains ethereal solution with redox mediator that enables oxidation of Li2O2 at low potentials. The electrodes are separated by a solid electrolyte membrane, allowing free transport of Li ions. This approach increases cycle life of lithium oxygen cells and their energy efficiency.
Role of Ionic Functional Groups on Ion Transport at Perovskite Interfaces
Authors: Liu Yao , Renna Lawrence A. , Thompson Hilary B. , Page Zachariah A. , Emrick Todd , Barnes Michael D. , Bag Monojit , Venkataraman D. , Russell Thomas P.
Published: August 2017

Hybrid organic/inorganic perovskite solar cells are invigorating the photovoltaic community due to their remarkable properties and efficiency. However, many perovskite solar cells show an undesirable current–voltage (I–V) hysteresis in their forward and reverse voltage scans, working to the detriment of device characterization and performance. This hysteresis likely arises from slow ion migration in the bulk perovskite active layer to interfaces which may induce charge trapping. It is shown that interfacial chemistry between the perovskite and charge transport layer plays a critical role in ion transport and I–V hysteresis in perovskite‐based devices. Specifically, phenylene vinylene polymers containing cationic, zwitterionic, or anionic pendent groups are utilized to fabricate charge transport layers with specific interfacial ionic functionalities. The interfacial‐adsorbing boundary induced by the zwitterionic polymer in contact with the perovskite increases the local ion concentration, which is responsible for the observed I–V hysteresis. Moreover, the ion adsorbing properties of this interface are exploited for perovskite‐based memristors. This fundamental study of I–V hysteresis in perovskite‐based devices introduces a new mechanism for inducing memristor behavior by interfacial ion adsorption.
High‐Performance and Breathable Polypyrrole Coated Air‐Laid Paper for Flexible All‐Solid‐State Supercapacitors
Authors: Chen Yuanxun , Cai Kefeng , Liu Congcong , Song Haijun , Yang Xiaowei
Published: August 2017

High‐performance, breathable, conductive, and flexible polypyrrole (PPy) coated paper electrodes are prepared by an interfacial polymerization method using air‐laid paper as a substrate. Owing to the synergistic effect of superior electrical conductivity, high wettability, and the porous architecture, the prepared electrode not only shows an outstanding specific capacitance and rate abilities (3100 and 2579 mF cm−2 at 1 and 20 mA cm−2 for a PPy coated paper electrode), but also exhibits excellent flexibility, wearability, and breathability. Based on these superior features, an all‐solid‐state supercapacitor assembled with the PPy coated paper electrodes shows an outstanding energy density of 62.4 µW h cm−2, remarkable air permeability and excellent flexibility to sustain various deformations. Furthermore, large‐scale fabrication of conductive flexible paper electrode can be easily achieved through this method. Therefore, this work offers a new vision for flexible energy storage.
Risk factors and a prognostic model for postsplenectomy survival in myelofibrosis
Authors: Tefferi Ayalew , Mudireddy Mythri , Gangat Naseema , Hanson Curtis A. , Ketterling Rhett P. , Pardanani Animesh , Nagorney David M.
Published: August 2017

Palliative treatment in myelofibrosis (MF) includes transfusion support, JAK2 inhibitors, involved field radiotherapy and splenectomy. To assist in selecting patients who are likely to benefit from splenectomy, we looked into risk factors for postsplenectomy survival, in 120 consecutive cases (median age 66 years); at the time of splenectomy, 61% displayed red cell transfusion need, 49% platelet count <100 × 10(9)/L, 25% leukocyte count >25 × 10(9)/L, 60% constitutional symptoms and 13% circulating blasts ≥5%; dynamic international prognostic scoring system risk categories were 21% high, 55% intermediate‐2, 21% intermediate‐1 and 3% low. Among informative cases, karyotype was abnormal in 60% and driver mutational status was JAK2 75%, CALR 15%, MPL 4% and triple‐negative 6%. At median follow‐up of 1.3 years, from time of splenectomy, 95 (79%) deaths and 30 (25%) leukemic transformations were recorded. Median postsplenectomy survival was 1.5 years; in multivariable analysis, survival was adversely affected by age >65 years, transfusion need, leukocyte count >25 × 10(9)/L and circulating blasts ≥5%; these variables were subsequently used to devise an HR‐weighted scoring system with high (3‐4 risk factors), intermediate (2 risk factors) and low (0‐1 risk factors) risk categories; the corresponding postsplenectomy median survivals were 0.3 (HR 5.9, 95% CI 3.2‐11.0), 1.3 (HR 2.9, 95% CI 1.8‐4.6) and 2.9 years. Postsplenectomy survival was not affected by driver mutational status or occurrence of leukemic transformation. Leukemia‐free survival was predicted by very high risk karyotype. The observations from the current study might help identify appropriate candidates for splenectomy in MF.
High mortality associated with tapeworm parasitism in geladas (Theropithecus gelada) in the Simien Mountains National Park, Ethiopia
Authors: Schneider‐Crease India , Griffin Randi H. , Gomery Megan A. , Bergman Thore J. , Beehner Jacinta C.
Published: August 2017

Despite increasing appreciation for parasitism as an important component of primate ecology and evolution, surprisingly few studies have demonstrated the costs of helminth parasitism in primates. Detecting parasite‐related costs in primates is particularly difficult because it requires detailed, long‐term data on individual host reproductive success, survival, and parasitism. The identification of the larval tapewormTaenia serialisin geladas under intensive long‐term study in the Ethiopian Highlands (Nguyen et al. [2015] American Journal of Primatology, 77:579–594; Schneider‐Crease et al. [2013] Veterinary Parasitology 198:240–243) provides an opportunity to examine how an endemic parasite impacts host reproductive success and survival. We used survival analyses to assess the mortality risk associated with protuberant larval cysts characteristic ofT. serialisusing a decade of data from a gelada population in the Simien Mountains National Park (SMNP), Ethiopia. We demonstrated strikingly high mortality associated withT. serialiscysts in adult females, particularly for younger adults. The estimated effect of cysts on male mortality was similar, although the effect was not statistically significant, likely owing to the smaller sample size. Additionally, the offspring of mothers with cysts experienced increased mortality, which was driven almost entirely by maternal death. Mothers with cysts had such high mortality that they rarely completed an interbirth interval. Comparison with a study of this parasite in another gelada population on the Guassa Plateau (Nguyen et al. [2015] American Journal of Primatology, 77:579–594) revealed lower cyst prevalence in the SMNP and similar cyst‐associated mortality. However, many more females with cysts completed interbirth intervals at Guassa than in the SMNP, suggesting thatT. serialiscysts may kill hosts more rapidly in the SMNP. Our results point toward the underlying causes of individual and population‐level heterogeneity inT. serialis‐associated mortality as important areas for future research.
Highly Selective Artificial Potassium Ion Channels Constructed from Pore‐Containing Helical Oligomers
Authors: Lang Chao , Deng Xiaoli , Yang Feihu , Yang Bing , Wang Wei , Qi Shuaiwei , Zhang Xin , Zhang Chenyang , Dong Zeyuan , Liu Junqiu
Published: August 2017

Potassium ion channels specifically transport K+ ions over Na+ ions across a cell membrane. A queue of four binding sites in the K+ channel pore plays significant roles during highly selective conduction. A kind of aromatic helical oligomer was synthesized that can selectively bind K+ over Na+. By aromatic stacking of helical oligomers, a type of artificial K+ channels with contiguous K+ binding sites was constructed. Such artificial channels exhibited exceptionally high K+/Na+ selectivity ratios during transmembrane ion conduction.
A Suite of “Minimalist” Photo‐Crosslinkers for Live‐Cell Imaging and Chemical Proteomics: Case Study with BRD4 Inhibitors
Authors: Pan Sijun , Jang Se‐Young , Wang Danyang , Liew Si Si , Li Zhengqiu , Lee Jun‐Seok , Yao Shao Q.
Published: August 2017

Affinity‐based probes (AfBPs) provide a powerful tool for large‐scale chemoproteomic studies of drug–target interactions. The development of high‐quality probes capable of recapitulating genuine drug–target engagement, however, could be challenging. “Minimalist” photo‐crosslinkers, which contain an alkyl diazirine group and a chemically tractable tag, could alleviate such challenges, but few are currently available. Herein, we have developed new alkyl diazirine‐containing photo‐crosslinkers with different bioorthogonal tags. They were subsequently used to create a suite of AfBPs based on GW841819X (a small molecule inhibitor of BRD4). Through in vitro and in situ studies under conditions that emulated native drug–target interactions, we have obtained better insights into how a tag might affect the probe's performance. Finally, SILAC‐based chemoproteomic studies have led to the discovery of a novel off‐target, APEX1. Further studies showed GW841819X binds to APEX1 and caused up‐regulation of endogenous DNMT1 expression under normoxia conditions.
Atomic‐Level Insight into Optimizing the Hydrogen Evolution Pathway over a Co1‐N4 Single‐Site Photocatalyst
Authors: Cao Yuanjie , Chen Si , Luo Qiquan , Yan Huan , Lin Yue , Liu Wei , Cao Linlin , Lu Junling , Yang Jinlong , Yao Tao , Wei Shiqiang
Published: August 2017

Knowledge of the photocatalytic H2 evolution mechanism is of great importance for designing active catalysts toward a sustainable energy supply. An atomic‐level insight, design, and fabrication of single‐site Co1‐N4 composite as a prototypical photocatalyst for efficient H2 production is reported. Correlated atomic characterizations verify that atomically dispersed Co atoms are successfully grafted by covalently forming a Co1‐N4 structure on g‐C3N4 nanosheets by atomic layer deposition. Different from the conventional homolytic or heterolytic pathway, theoretical investigations reveal that the coordinated donor nitrogen increases the electron density and lowers the formation barrier of key Co hydride intermediate, thereby accelerating H–H coupling to facilitate H2 generation. As a result, the composite photocatalyst exhibits a robust H2 production activity up to 10.8 μmol h−1, 11 times higher than that of pristine counterpart.
A Simple Route to Calcium and Strontium Hydride Clusters
Authors: Maitland Brant , Wiesinger Michael , Langer Jens , Ballmann Gerd , Pahl Jürgen , Elsen Holger , Färber Christian , Harder Sjoerd
Published: August 2017

The first strontium hydride complex has been obtained by simply treating Sr[N(SiMe3)2]2 with PhSiH3 in the presence of PMDTA. The Sr complex Sr6H9[N(SiMe3)2]3⋅(PMDTA)3 crystallizes as an “inverse cryptand”: an interstitial H− is surrounded by a Sr6H84+ cage decorated with amide and PMDTA ligands. The analogous Ca complex could also be obtained and both retain their solid‐state structures in solution: 1H NMR spectra in C6D6 show two doublets and one nonet (4:4:1). Up to 90 °C, no coalescence is observed. The Ca cluster was investigated by DFT calculations and shows atypically low charges on Ca (+1.14) and H (−0.59) which signifies an unexpectedly low ionicity. AIM analysis shows hydride⋅⋅⋅hydride bond paths with considerable electron densities in the bond critical point. The clusters thermally decompose into larger, undefined, metal hydride aggregates.
Highly Regioselective Alkylation of Hexabenzocoronenes: Fundamental Insights into the Covalent Chemistry of Graphene
Authors: Holzwarth Johannes , Amsharov Konstantin Yu. , Sharapa Dmitry I. , Reger David , Roshchyna Kateryna , Lungerich Dominik , Jux Norbert , Hauke Frank , Clark Timothy , Hirsch Andreas
Published: August 2017

Hexa‐peri‐hexabenzocoronides (HBC) was successfully used as a model system for investigating the complex mechanism of the reductive functionalization of graphene. The well‐defined molecular HBC system enabled deeper insights into the mechanism of the alkylation of reductively activated nanographenes. The separation and complete characterization of alkylation products clearly demonstrate that nanographene functionalization proceeds with exceptionally high regio‐ and stereoselectivities on the HBC scaffold. Experimental and theoretical studies lead to the conclusion that the intact basal graphene plane is chemically inert and addend binding can only take place at either preexisting defects or close to the periphery.
Asymmetric Synthesis of Tertiary Alcohols and Thiols via Nonstabilized Tertiary α‐Oxy‐ and α‐Thio‐Substituted Organolithium Species
Authors: Pulis Alexander P. , Varela Ana , Citti Cinzia , Songara Pradip , Leonori Daniele , Aggarwal Varinder K.
Published: August 2017

Nonstabilized α‐O‐substituted tertiary organolithium species are difficult to generate, and the α‐S‐substituted analogues are configurationally unstable. We now report that they can both be generated easily and trapped with a range of electrophiles with high enantioselectivity, providing ready access to a range of enantioenriched tertiary alcohols and thiols. The configurational stability of the α‐S‐organolithium species was enhanced by using a less coordinating solvent and short reaction times.
Reductive Decarboxylative Alkynylation of N‐Hydroxyphthalimide Esters with Bromoalkynes
Authors: Huang Liangbin , Olivares Astrid M. , Weix Daniel J.
Published: August 2017

A new method for the synthesis of terminal and internal alkynes from the nickel‐catalyzed decarboxylative coupling of N‐hydroxyphthalimide esters and bromoalkynes is presented. This reductive cross‐electrophile coupling is the first to use a C(sp)−X electrophile, and appears to proceed via an alkynylnickel intermediate. The internal alkyne products are obtained in yields of 41–95 % without the need for a photocatalyst, light, or a strong oxidant. The reaction displays a broad scope of carboxylic acid and alkyne coupling partners, and can tolerate an array of functional groups, including carbamate NH, halogen, nitrile, olefin, ketone, and ester moieties. Mechanistic studies suggest that this process does not involve an alkynylmanganese reagent and instead proceeds through nickel‐mediated bond formation.
A Convenient Route to Mixed Pnictogenylboranes
Authors: Hegen Oliver , Marquardt Christian , Timoshkin Alexey Y. , Scheer Manfred
Published: August 2017

We report on the synthesis and characterization of mixed pnictogenylboranes. The substitution of the Lewis base SMe2 in (OC)5W–PH2BH2–SMe2 (2) by different pnictogenylboranes ER2BH2–LB (E=P, As, Sb) leads to the Lewis acid/base stabilized butane analogue (OC)5W–PH2BH2ER2BH2–LB (3 a, b: E=P; R=H, SiMe3; LB=NMe3; 4 a, b: E=As; R=H, SiMe3; LB=NMe3; 5: E=Sb; R=SiMe3; LB=NHCMe). All of these compounds were characterized by single‐crystal X‐ray structure analysis, mass spectrometry, NMR, and IR spectroscopy. In addition, the very unstable phosphanylborane chain PH2BH2PH2BH2–NMe3 (1) was synthesized. DFT calculations provide insight into the thermodynamics of these reactions.
In situ electrical resistance and X‐ray tomography study of copper–tin polymer composites during thermal annealing
Authors: Yang Qing , Beers Megan Hoarfrost , Zheng Min , Lloyd Richard , Gao Ting , Parkinson Dilworth
Published: August 2017

In situ electrical conductivity and X‐ray tomography experiments are conducted on a conductive polymer composite containing polyvinylidene fluoride (PVDF) copolymer, copper (Cu), and tin (Sn) during thermal annealing. During annealing, the electrical resistivity drops by an order of magnitude, while X‐ray tomography, electron microscopy, and spectroscopy results show increasingly homogeneous dispersion of Sn in the conductive filler network, accompanied by the formation of Cu–Sn intermetallic around Cu and Sn particles. This study provides detailed insight into the morphological origins of the beneficial effect of thermal annealing on the electrical properties of conductive composites containing low melting metal fillers. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45399.
Multilayer structures based on annealed electrospun biopolymer coatings of interest in water and aroma barrier fiber‐based food packaging applications
Authors: Cherpinski Adriane , Torres‐Giner Sergio , Cabedo Luis , Méndez Jose Alberto , Lagaron Jose M.
Published: August 2017

In this research work, for the first time, a fiber‐based packaging material was coated by annealed electrospun ultrathin fibers of poly(3‐hydroxybutyrate), poly(vinyl alcohol), and polylactide. The resultant mono‐ and multilayer structures self‐adhered to the paper substrate and were characterized in terms of morphology, optical, and barrier properties. Additionally, the use of a static flat plate and rotating mandrel collector as well as the application of different electrospinning deposition times were analyzed. The thermally treated electrospun biopolymers yielded totally transparent films while, due to the opaque nature of the uncoated paper substrate, the developed packaging materials were also opaque but with a glossier surface finish provided by the bioplastic coating. The annealed films obtained from random electrospun fibers, that is, the mats of ultrathin fibers collected on the static plate, presented higher transparency and thickness and also enhanced barrier performance. On the overall, the developed annealed electrospun biopolymer coatings resulted in a significant improvement of the paper barrier properties to water and limonene vapors, being the paper/poly(vinyl alcohol)/poly(3‐hydroxybutyrate) film the best performing multilayer packaging structure. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45501.
Toward the operationalization of visual metaphor
Authors: Hiniker Alexis , Hong Sungsoo (Ray) , Kim Yea‐Seul , Chen Nan‐Chen , West Jevin D. , Aragon Cecilia
Published: August 2017

Many successful digital interfaces employ visual metaphors to convey features or data properties to users, but the characteristics that make a visual metaphor effective are not well understood. We used a theoretical conception of metaphor from cognitive linguistics to design an interactive system for viewing the citation network of the corpora of literature in the JSTOR database, a highly connected compound graph of 2 million papers linked by 8 million citations. We created 4 variants of this system, manipulating 2 distinct properties of metaphor. We conducted a between‐subjects experimental study with 80 participants to compare understanding and engagement when working with each version. We found that building on known image schemas improved response time on look‐up tasks, while contextual detail predicted increases in persistence and the number of inferences drawn from the data. Schema‐congruency combined with contextual detail produced the highest gains in comprehension. These findings provide concrete mechanisms by which designers presenting large data sets through metaphorical interfaces may improve their effectiveness and appeal with users.
Magnetosensitivity of bacteria E. coli: Magnetic isotope and magnetic field effects
Authors: Letuta Ulyana G. , Berdinskiy Vitaly L.
Published: August 2017

The biological effects of a 25Mg nuclear spin and weak magnetic fields have been found and studied by using bacterial cells of Escherichia coli (E. coli) grown on standard M9 nutrient media with different isotopes of magnesium: 24Mg, 25Mg, 26Mg, and a natural mixture of Mg isotopes. Among these isotopes only 25Mg has a nuclear spin I = 5/2 and nuclear magnetic moment which have been known to affect enzymatic processes in vitro due to hyperfine interactions with uncoupled electrons of substrates. Other non‐magnetic magnesium isotopes, 24Mg and 26Mg, have neither a nuclear spin (I = 0) nor a nuclear magnetic moment. Bacterial cells grown on 25Mg‐media and enriched with this isotope manifest a higher growth rate and colony‐forming units (CFU) compared with cells grown on media containing nonmagnetic 24Mg and 26Mg isotopes. Magnetic field dependencies of CFU cells enriched with different magnesium isotopes have been obtained. The observed isotope‐dependent differences are explained by intracellular enzymatic ion‐radical reactions which are magnetic field and nuclear spin sensitive. Enzymatic synthesis of ATP is considered as the most probable magnetosensitive biochemical process in vivo as far as effectiveness of ATP production is concerned; it determines the viability of cells and was shown in vitro as a nuclear spin‐dependent reaction. Bioelectromagnetics. 38:581–591, 2017. © 2017 Wiley Periodicals, Inc.