bluuebunny/crossref_metadata_2025 huggingface dataset:
Dendrimer‐Based Lipid Nanoparticles Deliver Therapeutic FAH mRNA to Normalize Liver Function and Extend Survival in a Mouse Model of Hepatorenal Tyrosinemia Type I
Authors: Cheng Qiang , Wei Tuo , Jia Yuemeng , Farbiak Lukas , Zhou Kejin , Zhang Shuyuan , Wei Yonglong , Zhu Hao , Siegwart Daniel J.
Published: October 2018

mRNA‐mediated protein replacement represents a promising concept for the treatment of liver disorders. Children born with fumarylacetoacetate hydrolase (FAH) mutations suffer from Hepatorenal Tyrosinemia Type 1 (HT‐1) resulting in renal dysfunction, liver failure, neurological impairments, and cancer. Protein replacement therapy using FAH mRNA offers tremendous potential to cure HT‐1, but is currently hindered by the development of effective mRNA carriers that can function in diseased livers. Structure‐guided, rational optimization of 5A2‐SC8 mRNA‐loaded dendrimer lipid nanoparticles (mDLNPs) increases delivery potency of FAH mRNA, resulting in functional FAH protein and sustained normalization of body weight and liver function in FAH−/− knockout mice. Optimization using luciferase mRNA produces DLNP carriers that are efficacious at mRNA doses as low as 0.05 mg kg−1 in vivo. mDLNPs transfect > 44% of all hepatocytes in the liver, yield high FAH protein levels (0.5 mg kg−1 mRNA), and are well tolerated in a knockout mouse model with compromised liver function. Genetically engineered FAH−/− mice treated with FAH mRNA mDLNPs have statistically equivalent levels of TBIL, ALT, and AST compared to wild type C57BL/6 mice and maintain normal weight throughout the month‐long course of treatment. This study provides a framework for the rational optimization of LNPs to improve delivery of mRNA broadly and introduces a specific and viable DLNP carrier with translational potential to treat genetic diseases of the liver.
Current‐Induced Skyrmion Generation through Morphological Thermal Transitions in Chiral Ferromagnetic Heterostructures
Authors: Lemesh Ivan , Litzius Kai , Böttcher Marie , Bassirian Pedram , Kerber Nico , Heinze Daniel , Zázvorka Jakub , Büttner Felix , Caretta Lucas , Mann Maxwell , Weigand Markus , Finizio Simone , Raabe Jörg , Im Mi‐Young , Stoll Hermann , Schütz Gisela , Dupé Bertrand , Kläui Mathias , Beach Geoffrey S. D.
Published: October 2018

Magnetic skyrmions promise breakthroughs in future memory and computing devices due to their inherent stability and small size. Their creation and current driven motion have been recently observed at room temperature, but the key mechanisms of their formation are not yet well‐understood. Here it is shown that in heavy metal/ferromagnet heterostructures, pulsed currents can drive morphological transitions between labyrinth‐like, stripe‐like, and skyrmionic states. Using high‐resolution X‐ray microscopy, the spin texture evolution with temperature and magnetic field is imaged and it is demonstrated that with transient Joule heating, topological charges can be injected into the system, driving it across the stripe‐skyrmion boundary. The observations are explained through atomistic spin dynamic and micromagnetic simulations that reveal a crossover to a global skyrmionic ground state above a threshold magnetic field, which is found to decrease with increasing temperature. It is demonstrated how by tuning the phase stability, one can reliably generate skyrmions by short current pulses and stabilize them at zero field, providing new means to create and manipulate spin textures in engineered chiral ferromagnets.
Nanoparticle‐Laden Macrophages for Tumor‐Tropic Drug Delivery
Authors: Zhang Weizhong , Wang Mengzhe , Tang Wei , Wen Ru , Zhou Shiyi , Lee Chaebin , Wang Hui , Jiang Wen , Delahunty Ian Michael , Zhen Zipeng , Chen Hongmin , Chapman Matthew , Wu Zhanhong , Howerth Elizabeth W. , Cai Houjian , Li Zibo , Xie Jin
Published: October 2018

Macrophages hold great potential in cancer drug delivery because they can sense chemotactic cues and home to tumors with high efficiency. However, it remains a challenge to load large amounts of therapeutics into macrophages without compromising cell functions. This study reports a silica‐based drug nanocapsule approach to solve this issue. The nanocapsule consists of a drug–silica complex filling and a solid silica sheath, and it is designed to minimally release drug molecules in the early hours of cell entry. While taken up by macrophages at high rates, the nanocapsules minimally affect cell migration in the first 6–12 h, buying time for macrophages to home to tumors and release drugs in situ. In particular, it is shown that doxorubicin (Dox) as a representative drug can be loaded into macrophages up to 16.6 pg per cell using this approach. When tested in a U87MG xenograft model, intravenously (i.v.) injected Dox‐laden macrophages show comparable tumor accumulation as untreated macrophages. Therapy leads to efficient tumor growth suppression, while causing little systematic toxicity. This study suggests a new cell platform for selective drug delivery, which can be readily extended to the treatment of other types of diseases.
A Facile, Low‐Cost Hot‐Pressing Process for Fabricating Lithium–Sulfur Cells with Stable Dynamic and Static Electrochemistry
Authors: Chung Sheng‐Heng , Lai Ke‐Yu , Manthiram Arumugam
Published: October 2018

Lithium–sulfur batteries are among the most promising low‐cost, high‐energy‐density storage devices. However, the inability to host a sufficient amount of sulfur in the cathode while maintaining good electrochemical stability under a lean electrolyte condition has limited the progress. The main cause of these challenges is the sensitivity of the sulfur cathode to the cell‐design parameters (i.e., the amount of sulfur and electrolyte) and the experimental testing conditions (i.e., cycling rates and analysis duration). Here, a hot‐pressing method is presented that effectively encapsulates a high amount of sulfur in the cathode within only 5 s, resulting in high sulfur loading and content of, respectively, 10 mg cm−2 and 65 wt%. The hot‐pressed sulfur (HPS) cathodes exhibit superior dynamic and static electrochemical performance under a broad cycling‐rate (C/20–1C rates) and low electrolyte/sulfur ratio (6 µL mg−1) conditions. The dynamic cell stability is demonstrated by high gravimetric and areal capacities of, respectively, 415–730 mAh g−1 and 7–12 mAh cm−2 at C/20–1C rates with a high capacity retention of over 70% after 200 cycles. The static cell stability is demonstrated by excellent shelf life with low self‐discharge and stable cycle life on storing for over one year.
Oxygen Vacancies Allow Tuning the Work Function of Vanadium Dioxide
Authors: Wang Rongbin , Katase Takayoshi , Fu Ke‐Ke , Zhai Tianshu , Yang Jiacheng , Wang Qiankun , Ohta Hiromichi , Koch Norbert , Duhm Steffen
Published: October 2018

The evolution of electron valence bands, core levels, and work function of vanadium dioxide (VO2) thin films upon argon ion sputtering and annealing, as commonly done to obtain atomically clean surfaces, with and without low‐pressure oxygen atmosphere during annealing is investigated by ultraviolet and X‐ray photoemission spectroscopy. Both sputtering and annealing in vacuum introduce lower oxidation state V species, leading to an increased intensity of V 3d derived bands close to the Fermi level. Such oxygen deficient surfaces exhibit low work function values as low as 4.40 eV. Annealing the sample under low‐pressure oxygen atmosphere (few times 10−4 mbar partial O2 pressure) results in stoichiometric VO2 surfaces with a high work function of up to 6.70 eV. Moreover, the work function of the VO2 can be continuously tuned between the high and low limits by adjusting the atomic ratio of oxygen and vanadium at the surface. Appropriately adjusted VO2 can thus be employed as moderate electron as well as superior hole injecting electrode material in electronic and optoelectronic devices.
Robust and Flexible Micropatterned Electrodes and Micro‐Supercapacitors in Graphene–Silk Biopapers
Authors: Ma Ruilong , Gordon Daniel , Yushin Gleb , Tsukruk Vladimir V.
Published: October 2018

Robust and flexible micro‐supercapacitors based upon a graphene oxide–silk layered bionanocomposite is reported. Generation of micropatterned electrodes with sub‐micrometer spatial resolution is accomplished using a novel resist‐stenciling technique, enabling the transfer of complex microcircuit designs to a graphene oxide–silk layered substrate as chemically reduced features microfeatures across wafer‐length scales. Resist‐stenciling can produce micropatterned reduction features with over ten times the feature density compared to techniques such as laser‐scribing or screen printing. As a proof‐of‐concept, resist‐stenciling is used to fabricate the first 2D micro‐supercapacitors integrated into a layered graphene bionanocomposite. These demonstrate a specific capacitance of ≈128 F g−1, good capacitance retention under charge cycling (87.5% after 2000 cycles), and repeated mechanical bending without failure. Resist‐stenciling leverages tools currently in use by the microelectronics industry to enable the scalable, high‐resolution conversion of layered nanocomposites into microelectronic circuit, storage, and sensing elements.
Development and Characterization of 3D Printable Thermite Component Materials
Authors: Durban Matthew M. , Golobic Alexandra M. , Bukovsky Eric V. , Gash Alexander E. , Sullivan Kyle T.
Published: October 2018

Additive manufacturing (AM) has recently shown great promise as a means to tailor a wide range of material properties, both quasi‐static and dynamic. An example of controlling the dynamic behavior is to tailor the chemical energy release rate in composite energetic materials such as thermites – which are a subset of pyrotechnics that use a metal fuel and a metal oxide as an oxidizer. Since these materials are most hazardous once finely mixed, the approach taken here is to formulate the fuel and oxidizer separately such that they can be mixed on‐the‐fly. Herein, the development, formulation, and characterization of two respective aqueous 3D printable inks consisting of Al and CuO are discussed. The rheological properties and ability of the material to span gaps are characterized. To demonstrate that the materials could be mixed and sustain a reaction, the inks are fed into a static mixing nozzle and extruded into a high‐aspect ratio test strip. Upon drying, the material can be ignited and sustain a propagation through the part. These results present a facile, and safe, way to AM thermite which can be used for more detailed follow on studies looking at the role of architecture on the reactivity.
Graphene‐Based Planar Microsupercapacitors: Recent Advances and Future Challenges
Authors: Liang Jiaxing , Mondal Anjon Kumar , Wang Da‐Wei , Iacopi Francesca
Published: October 2018

The continuous development of integrated electronics such as maintenance‐free biosensors, remote and mobile environmental sensors, wearable personal electronics, nanorobotics etc. and their continued miniaturization has led to an increasing demand for miniaturized energy storage units. Microsupercapacitors with graphene electrodes hold great promise as miniaturized, integrated power sources thanks to their fast charge/discharge rates, superior power performance, and long cycling stability. In addition, planar interdigitated electrodes also have the capability to reduce ion diffusion distances leading to a greatly improved electrochemical performance. Either as standalone power sources or complementing energy harvesting units, it is expected that graphene‐based microsupercapacitors will play a key role as miniaturized power sources in electronic microsystems. This review highlights the recent development, challenges, and perspectives in this area, with an emphasis on the link between material and geometry design of planar graphene‐based electrodes and their electrochemical performance and integrability.
Selective Oxidation and Carbonization by Laser Writing into Porous Silicon
Authors: Keating Adrian , Sun Xiao
Published: October 2018

The selective formation of either oxidized or carbonized features into 2.5 µm thick porous silicon (PS) films using laser writing at a wavelength of 405 nm is demonstrated. Oxidized features are formed in air while carbonized features are achieved during the flow of propane at 600 sccm. Voids which have been previously associated with the use of propane are not observed, largely due to the rapid heating and high flow rates achieved in the experiment. Carbonized regions with feature widths down to 1.8 µm are achieved and chemical resistance to both hydrofluoric acid and potassium hydroxide is demonstrated. Once carbonized regions are formed, the surrounding areas can be overwritten in air to convert the surrounding regions into oxidized PS allowing films to be created with as‐fabricated, oxidized and carbonized regions. Energy dispersive X‐ray and Raman analysis confirms the presence of carbon within the written structures. At high optical powers, cracking around the carbonized features is observed which is attributed to a contraction of the film. Such cracking is not observed during selective oxidation of features. This work significantly enhances the ability to engineer and pattern the composition of PS films enabling selective control of the material's properties and functionality.
Piezoelectric Buckled Beam Array on a Pacemaker Lead for Energy Harvesting
Authors: Dong Lin , Wen Chunsheng , Liu Yin , Xu Zhe , Closson Andrew B. , Han Xiaomin , Escobar Gladys Patricia , Oglesby Meagan , Feldman Marc , Chen Zi , Zhang John X. J.
Published: October 2018

Self‐sustainable energy generation represents a new frontier to significantly extend the lifetime and effectiveness of implantable biomedical devices. In this work, a piezoelectric energy harvester design is employed to utilize the bending of the lead of a cardiac pacemaker or defibrillator for generating electrical energy with minimal risk of interfering with cardiovascular functions. The proposed energy harvester combines flexible porous polyvinylidene fluoride–trifluoroethylene thin film with a buckled beam array design for potentially harvesting energy from cardiac motion. Systematic in vitro experimental evaluations are performed by considering complex parameters in practical implementations. Under various mechanical inputs and boundary conditions, the maximum electrical output of this energy harvester yields an open circuit voltage (peak to peak) of 4.5 V and a short circuit current (peak to peak) of 200 nA, and that energy is sufficient to self‐power a typical pacemaker for 1 d. A peak power output of 49 nW is delivered at an optimal resistor load of 50 MΩ. The scalability of the design is also discussed, and the reported results demonstrate the energy harvester's capability of providing significant electrical energy directly from the motions of pacemaker leads, suggesting a paradigm for biomedical energy harvesting in vivo.
Nonmetallic Materials for Plasmonic Hot Carrier Excitation
Authors: Ishii Satoshi , Shinde Satish Laxman , Nagao Tadaaki
Published: October 2018

Optical excitation of hot carriers in metals can be achieved even with low energy photons. When a metal comes in contact with a semiconductor, carrier injection can take place from the metal to the semiconductor even with photons possessing sub‐bandgap energies. While such internal photoemission has several decades of history, recent advances in plasmonics have brought the study of internal photoemission into a new era. The efficiency of hot carrier excitation can be improved drastically by rationally fabricating a metallic nanostructure to excite plasmon resonances. Moreover, the heating caused by the relaxation of plasmonic hot carriers is highly localized. These plasmon enhanced photoelectric and photothermal conversions have been studied intensively from fundamental and application‐oriented viewpoints, wherein gold and silver have been exclusively used. By contrast, this progress report covers nonmetallic materials that can be used for plasmon enhanced photoelectric and photothermal conversions. The main nonmetallic materials covered herein are transition metal nitrides, transition metal carbides, and metal oxides. Although research on nonmetallic materials for photoelectric and photothermal conversions is in the preliminary stage, some nonmetallic materials have been shown to outperform gold. This progress report aims to highlight the recent progress and discuss future research directions.
Designer Perfect Light Absorption Using Ultrathin Lossless Dielectrics on Absorptive Substrates
Authors: ElKabbash Mohamed , Iram Shamreen , Letsou Theodore , Hinczewski Michael , Strangi Giuseppe
Published: October 2018

Optical absorbers comprised of an ultrathin lossy dielectric film on an opaque metallic substrate are an attractive alternative to lithographically intense metamaterial and nanoplasmonic optical absorbers as they allow for large‐scale, cost‐effective fabrication. However, requiring that the dielectric is lossy and the metallic substrate is highly reflective but not a perfect electric conductor (PEC) limits the wavelength range and materials that can be used to realize strong to perfect light absorption. In this work, we theoretically and experimentally investigate light absorption using ultrathin lossless dielectric films. By choosing proper lossless ultrathin dielectrics and substrates, iridescence free, perfect light absorption is possible over the visible, near infrared (NIR), and short‐wave infrared (SWIR) wavelength ranges with designer absorption properties. The proposed class of ultrathin film absorbers relaxes many constraints on the type of materials used to realize perfect light absorption. The flexibility of our design makes it relevant for many applications specifically in structural coloring, selective thermal emission, thermo‐photovoltaics, photo‐thermoelectric generation, and gas sensing.
Electrical Control of Unpolarized Reflectivity in Polymer‐Stabilized Cholesteric Liquid Crystals at Oblique Incidence
Authors: Tondiglia Vincent P. , Rumi Mariacristina , Idehenre Ighodalo U. , Lee Kyung Min , Binzer John F. , Banerjee Partha P. , Evans Dean R. , McConney Michael E. , Bunning Timothy J. , White Timothy J.
Published: October 2018

The cholesteric liquid crystal phase at or near normal incidence selectively reflects circularly polarized light matching the handedness of the helicoidal superstructure. At large angles of incidence, both senses of circularly polarized light are reflected over a certain wavelength range. Stabilizing the cholesteric liquid crystal phase with low concentrations of polymer network that maintains structural chirality allows the pitch (and accordingly, the selective reflection) to be adjusted with an electric field. Here, the behavior of these polymer stabilized cholesteric liquid crystals is investigated at large angles of incidence, to determine how the total reflection evolves when the polymer network is deformed by an external DC field. Strong, unpolarized reflection is observed in polymer stabilized cholesteric liquid crystals at oblique angles over a wide range of field values. As the application of a DC electric field can adjust the position or bandwidth of the total reflection in polymer stabilized cholesteric liquid crystals, these reconfigurable devices could find potential end use in optical applications where polarization independent properties are needed, such as spectroscopy and polarimetry.
Liquid Crystal Pancharatnam–Berry Micro‐Optical Elements for Laser Beam Shaping
Authors: Jiang Miao , Yu Hao , Feng Xiayu , Guo Yubing , Chaganava Irakli , Turiv Taras , Lavrentovich Oleg D. , Wei Qi‐Huo
Published: October 2018

Shaping the intensity profile of a laser beam is desired by various industrial applications. In this paper, a new approach is presented to design and fabricate liquid crystal (LC) micro‐optical elements (MOEs) with engineered Pancharatnam–Berry (PB) phases for beam shaping. By generalizing the Snell's law for spatially variant PB phases, molecular orientation patterns are designed for the liquid crystal MOEs to shape a Gaussian laser beam into flattop intensity profiles with circular and square cross‐sections, with the β parameter varied from 4 to 42. It is demonstrated that such liquid crystal beam shaping MOEs can be fabricated with high throughput and high resolution by using a photopatterning technique based on plasmonic metamasks and that they produce excellent beam quality, no zero‐order light leakage with a beam size from 10 to 600 µm. As the plasmonic metamasks allow for encoding arbitrary molecular orientations, i.e., arbitrary geometric phase profiles, the approaches presented here are widely applicable to large‐scale manufacturing of liquid crystal MOEs for any beam shapes.
Advances in Porous Silicon–Based Nanomaterials for Diagnostic and Therapeutic Applications
Authors: Tieu Terence , Alba Maria , Elnathan Roey , Cifuentes‐Rius Anna , Voelcker Nicolas H.
Published: October 2018

This review provides a perspective on porous silicon (pSi)–based nanomaterials including nanoparticles, nanowires, and thin films, that are currently being used in advanced therapy, imaging, and sensing, with a focus on their effective use in future clinical settings. The achievement of both controlled geometry and architecture, and surface chemistry motifs, are presented as the two key parameters that dictate the nature of interactions with the biological entities. The authors discuss the role of the degradation kinetics in a biological environment into nontoxic by‐products. pSi is presented as increasingly fulfilling a central task in various biomedical applications and clinical settings, owing to its unique physiochemical properties.
Modeling of Soft Sample Deformation in Atomic Force Microscope Imaging: Live Mammalian Cell Example
Authors: Ren Juan , Zou Qingze
Published: October 2018

A model of the scanning‐caused soft sample deformation during atomic force microscope contact‐mode (CM) imaging is developed. CM imaging has been widely used for topography characterization of live biological samples such as live cells. However, due to the intrinsic softness of these samples, the sample surface deformation caused by the probe–sample interaction leads to significant error in the topography images obtained, and damage to the live biological sample. Although the deformation can be reduced by imaging at a rather slow scan rate (e.g., less than 0.2 Hz), such a low‐speed imaging not only is time consuming, but also inevitably induces large temporal error. In this work, the scanning‐caused surface deformation of soft samples is modeled and quantified, including live biological samples in CM imaging. Effects of both the scanning and the coupling between the vertical and the lateral deformation on the deformation are characterized. The proposed deformation model is validated by implementing it to quantify the topography image difference caused by the scanning‐caused surface deformation of live prostate cancer cells imaged at two different (high and low) speeds, respectively.
Designing Magnetic Anisotropy through Strain Doping
Authors: Herklotz Andreas , Gai Zheng , Sharma Yogesh , Huon Amanda , Rus Stefania F. , Sun Lu , Shen Jian , Rack Philip D. , Ward Thomas Z.
Published: October 2018

The coupling between a material's lattice and its underlying spin state links structural deformation to magnetic properties; however, traditional strain engineering does not allow the continuous, post‐synthesis control of lattice symmetry needed to fully utilize this fundamental coupling in device design. Uniaxial lattice expansion induced by post‐synthesis low energy helium ion implantation is shown to provide a means of bypassing these limitations. Magnetocrystalline energy calculations can be used a priori to estimate the predictive design of a material's preferred magnetic spin orientation. The efficacy of this approach is experimentally confirmed in a spinel CoFe2O4 model system where the epitaxial film's magnetic easy axis is continuously manipulated between the out‐of‐plane (oop) and in‐plane (ip) directions as lattice tetragonality moves from ip to oop with increasing strain doping. Macroscopically gradual and microscopically abrupt changes to preferential spin orientation are demonstrated by combining ion irradiation with simple beam masking and lithographic procedures. The ability to design magnetic spin orientations across multiple length scales in a single crystal wafer using only crystal symmetry considerations provides a clear path toward the rational design of spin transfer, magnetoelectric, and skyrmion‐based applications where magnetocrystalline energy must be dictated across multiple length scales.
Jammed Microgel Inks for 3D Printing Applications
Authors: Highley Christopher B. , Song Kwang Hoon , Daly Andrew C. , Burdick Jason A.
Published: October 2018

3D printing involves the development of inks that exhibit the requisite properties for both printing and the intended application. In bioprinting, these inks are often hydrogels with controlled rheological properties that can be stabilized after deposition. Here, an alternate approach is developed where the ink is composed exclusively of jammed microgels, which are designed to incorporate a range of properties through microgel design (e.g., composition, size) and through the mixing of microgels. The jammed microgel inks are shear‐thinning to permit flow and rapidly recover upon deposition, including on surfaces or when deposited in 3D within hydrogel supports, and can be further stabilized with secondary cross‐linking. This platform allows the use of microgels engineered from various materials (e.g., thiol‐ene cross‐linked hyaluronic acid (HA), photo‐cross‐linked poly(ethylene glycol), thermo‐sensitive agarose) and that incorporate cells, where the jamming process and printing do not decrease cell viability. The versatility of this particle‐based approach opens up numerous potential biomedical applications through the printing of a more diverse set of inks.
The Relation of Phase‐Transition Effects and Thermal Stability of Planar Perovskite Solar Cells
Authors: Qin Chuanjiang , Matsushima Toshinori , Klotz Dino , Fujihara Takashi , Adachi Chihaya
Published: October 2018

A power conversion efficiency of over 20% has been achieved in CH3NH3PbI3‐based perovskite solar cells (PSC), however, low thermal stability associated with the presence of a phase transition between tetragonal and cubic structures near room temperature is a major issue that must be overcome for future practical applications. Here, the influence of the phase transition on the thermal stability of PSCs is investigated in detail by comparing four kinds of perovskite films with different compositions of halogen atoms and organic components. Thermally stimulated current measurements reveal that a large number of carrier traps are generated in solar cells with the perovskite CH3NH3PbI3 as a light absorber after operation at 85 °C, which is higher than the phase‐transition temperature. Electrochemical impedance spectroscopy measurements further exclude effects of a possible morphology change on the formation of carrier traps. These carrier traps are detrimental to the thermal stability. The thermogravimetric analysis does not show a decomposition for any of the materials in the temperature range relevant for operation. The perovskite alloys do not have this phase transition, resulting in effectively suppressed formation of carrier traps. PSCs with improved thermal stability under the standard thermal cycling test are demonstrated.
Porous Organic Frameworks: Advanced Materials in Analytical Chemistry
Authors: Zhang Shuaihua , Yang Qian , Wang Chun , Luo Xiliang , Kim Jeonghun , Wang Zhi , Yamauchi Yusuke
Published: October 2018

Porous organic frameworks (POFs), a general term for covalent‐organic frameworks (COFs), covalent triazine frameworks (CTFs), porous aromatic frameworks (PAFs), etc., are constructed from organic building monomers with strong covalent bonds and have generated great interest among researchers. The remarkable features, such as large surface areas, permanent porosity, high thermal and chemical stability, and convenient functionalization, promote the great potential of POFs in diverse applications. A critical overview of the important development in the design and synthesis of COFs, CTFs, and PAFs is provided and their state‐of‐the‐art applications in analytical chemistry are discussed. POFs and their functional composites have been explored as advanced materials in “turn‐off” or “turn‐on” fluorescence detection and novel stationary phases for chromatographic separation, as well as a promising adsorbent for sample preparation methods. In addition, the prospects for the synthesis and utilization of POFs in analytical chemistry are also presented. These prospects can offer an outlook and reference for further study of the applications of POFs.
A Facile Approach to Improve Interchain Packing Order and Charge Mobilities by Self‐Assembly of Conjugated Polymers on Water
Authors: Yang Yizhou , Liu Zitong , Chen Jianmei , Cai Zhengxu , Wang Zhijie , Chen Wei , Zhang Guanxin , Zhang Xisha , Chi Lifeng , Zhang Deqing
Published: October 2018

Development of facile and economic approaches for assembling organic semiconductors into more ordered structures toward high charge mobilities is highly demanding for the fabrication of organic circuits. Here a simple and facile approach is reported to prepare conjugated polymer thin films with improved crystallinities and charge mobilities by self‐assembling semiconducting polymers on water. The formation of polymer thin films with more ordered structures is attributed to coffee ring effect induced by solvent‐evaporation on water, and the hydrophobic nature of conjugated polymers that forces the polymer chains to pack densely and orderly on water surface. This approach is applicable to typical semiconducting polymers, and charge mobilities of their thin films are boosted remarkably. Finally, this new method can be utilized to easily fabricate the array of field‐effect transistors with high charge mobilities in an economic way.
Solution‐Processed InAs Nanowire Transistors as Microwave Switches
Authors: Mirkhaydarov Bobur , Votsi Haris , Sahu Abhishek , Caroff Philippe , Young Paul R. , Stolojan Vlad , King Simon G. , Ng Calvin C. H. , Devabhaktuni Vijaya , Tan Hoe H. , Jagadish Chennupati , Aaen Peter H. , Shkunov Maxim
Published: October 2018

The feasibility of using self‐assembled InAs nanowire bottom‐gated field‐effect transistors as radio‐frequency and microwave switches by direct integration into a transmission line is demonstrated. This proof of concept is demonstrated as a coplanar waveguide (CPW) microwave transmission line, where the nanowires function as a tunable impedance in the CPW through gate biasing. The key to this switching capability is the high‐performance, low impedance InAs nanowire transistor behavior with field‐effect mobility of ≈300 cm2 V−1 s−1, on/off ratio of 103, and resistance modulation from only 50 Ω in the full accumulation mode, to ≈50 kΩ when the nanowires are depleted of charge carriers. The gate biasing of the nanowires within the CPW results in a switching behavior, exhibited by a ≈10 dB change in the transmission coefficient, S21, between the on/off switching states, over 5–33 GHz. This frequency range covers both the microwave and millimeter‐wave bands dedicated to Internet of things and 5G applications. Demonstration of these switches creates opportunities for a new class of devices for microwave applications based on solution‐processed semiconducting nanowires.
Selective CO2 Reduction on 2D Mesoporous Bi Nanosheets
Authors: Yang Hui , Han Na , Deng Jun , Wu Jinghua , Wang Yu , Hu Yongpan , Ding Pan , Li Yafei , Li Yanguang , Lu Jun
Published: October 2018

The conversion of CO2 to value‐added products using electrical or solar energy represents an attractive means for the capture and utilization of atmospheric CO2. Formate is a popular product from CO2 reduction, but its reaction selectivity is usually unsatisfactory. Tin‐based materials have attracted the most attention for formate production at present. Unfortunately, most of them only exhibit moderate selectivity in a narrow and highly cathodic potential window. In this study, it is demonstrated that traditionally under‐explored bismuth has a much greater potential for formate production than tin or other materials. Mesoporous bismuth nanosheets are prepared here by the cathodic transformation of atomic‐thick bismuth oxycarbonate nanosheets. They enable the selective CO2 reduction to formate with large current density, excellent Faradaic efficiency (≈100%) over a broad potential window and great operation stability. Moreover, Bi nanosheets are integrated with an oxygen evolution reaction electrocatalyst in full cells, and achieve efficient and robust solar conversion of CO2/H2O to formate/O2.
High‐Rate Performance and Ultralong Cycle Life Enabled by Hybrid Organic–Inorganic Vanadyl Ethylene Glycolate for Lithium‐Ion Batteries
Authors: Wang Xinran , Bi Xuanxuan , Zheng Shili , Wang Shaona , Zhang Yi , Du Hao , Lu Jun
Published: October 2018

Transition metal oxides (TMOs) possess high theoretical capacity and serve as promising anode candidates for lithium‐ion batteries. However, the intrinsic low conductivity handicaps the application of TMOs. Molecular modification by coupling TMOs structure with Li‐ion conductive polymer ligands can facilitate the kinetics of electrochemical lithiation/delithiation process. Herein, a proof‐of‐concept investigation on the Li‐ion storage capability by vanadyl ethylene glycolate (VEG) is achieved with the improvement of Li‐ion diffusion kinetics by modifiying the vanadium oxide with organic ligands. VEG demonstrates unprecedented advantage for fast rate capability, stable cycleability, and high capacity at both room temperarture (25 °C) and elevated temperature (60 °C).
Synergistic High‐Rate Solar Steaming and Mercury Removal with MoS2/C @ Polyurethane Composite Sponges
Authors: Li Weigu , Tekell Marshall C. , Huang Yun , Bertelsmann Karina , Lau Max , Fan Donglei
Published: October 2018

Solar steam generation, a sustainable water‐purification technology, holds substantial promise in resolving the global issue of shortage of drinkable water. Here, the design, fabrication, and high‐performance of an innovative 3D solar steamer, offering synergistic high‐efficiency steaming and heavy metal removal functions are reported. The device is made of synthesized carbon‐molybdenum‐disulfide microbeads electrostatically assembled on a 3D polyurethane sponge. The mesoporous composite sponge also serves as a freestanding water reservoir that avoids one‐side contact to bulk water, effectively suppressing the commonly observed parasitic heat loss, and offering a high energy efficiency of 88%. When being sculpted into a 3D spoke‐like structure, the composite sponge achieves one of the highest evaporation rates of 1.95 kg m−2 h−1 at 1 sun. The solar steamer is demonstrated for water treatment, i.e., decontamination of metal ions, disinfection, and reducing alkalinity and hardness of river water. Particularly, the strong mercury adsorption of MoS2 reduces mercury levels from 200 to 1 ppb, meeting the stringent standard set by the Environmental Protection Agency, which is the first demonstration of mercury‐removal powered by solar energy. The unique design, fabrication, water‐handling strategy, and mercury‐removal function of this high‐performance solar steamer can inspire new paradigms of water treatment technologies.
Direct Electricity Generation Mediated by Molecular Interactions with Low Dimensional Carbon Materials—A Mechanistic Perspective
Authors: Liu Albert Tianxiang , Zhang Ge , Cottrill Anton L. , Kunai Yuichiro , Kaplan Amir , Liu Pingwei , Koman Volodymyr B. , Strano Michael S.
Published: October 2018

Next‐generation off‐the‐grid electronic systems call for alternative modes of energy harvesting. The past two decades have witnessed the evolution of a wide spectrum of low dimensional carbon materials with extraordinary physical and chemical properties, ideal for microscale electrical energy storage and generation. Tremendous progress has been made in harnessing the energy associated with the interactions between these nanostructured carbon substrates and the surrounding molecular phases, subsequently converting them into useful electricity. This review summarizes the important theoretical and experimental milestones the field has reached to date, and further classifies these energy harvesting processes based on underlying physics, into five mechanistically distinct classes—phonon coupling, Coulombic scattering, electrokinetic streaming, asymmetric doping, and capacitive discharging. With a special mechanistic focus, the authors hope to resolve the fundamental attributes shared by this diverse array of molecular scale energy harvesting schemes, offer perspectives on key challenges, and ultimately establish design principles that guide further device optimization.
Effect of Heteroatom and Doping on the Thermoelectric Properties of Poly(3‐alkylchalcogenophenes)
Authors: Gregory Shawn A. , Menon Akanksha K. , Ye Shuyang , Seferos Dwight S. , Reynolds John R. , Yee Shannon K.
Published: October 2018

This study reports on the thermoelectric properties of poly(3‐alkylchalcogenophene) thin films (500 nm) as a function of heteroatom (sulfur, selenium, tellurium), and how these properties change with dopant (ferric chloride) concentration. UV–vis–NIR spectroscopy shows that polaronic charge carriers are formed upon doping. Poly(3‐alkyltellurophene) (P3RTe) is most easily doped followed by poly(3‐alkylselenophene) (P3RSe) and poly(3‐alkylthiophene) (P3RT), where R = 3,7‐dimethyloctyl chain is the pendant alkyl group. Thermoelectric properties vary as functions of the heteroatom and doping level. At low dopant concentrations (≈1 × 10−3
m), P3RTe shows the highest power factor of 10 µW m−1 K−2, while, at higher dopant concentrations (≈5 × 10−3
m), P3RSe shows the highest power factor of 13 µW m−1 K−2. Most notably, it is found that the measured properties are consistent with Mott's polaron hopping model and not consistent with other transport models. Additionally, temperature‐dependent conductivity measurements show that for a given dopant concentration, the activation energies for electronic transport decrease as the heteroatom is changed from sulfur to selenium to tellurium. Overall, this work presents a systematic study of poly(chalcogenophenes) and indicates the potential of polymers beyond P3HT by tuning the heteroatom and doping level for optimized thermoelectric performance.
Hybrid Graphene Ribbon/Carbon Electrodes for High‐Performance Energy Storage
Authors: Farquhar Anna K. , Supur Mustafa , Smith Scott R. , Van Dyck Colin , McCreery Richard L.
Published: October 2018

The utility of supercapacitors for both fixed and portable energy storage would be greatly enhanced if their energy density could be increased while maintaining their high power density, fast charging time, and low cost. This study describes a simple, solution‐phase, scalable modification of carbon materials by a covalently bonded “brush” of hydrogen‐terminated graphene ribbons (GRs) with layer thicknesses of 2–20 nm, resulting in a 20–100 times increase in the areal capacitance of the unmodified electrode surface. On a flat sp2 carbon surface modified by GRs, the capacitance exceeds 1200 µF cm−2 in 0.1 m H2SO4 due to a distinct type of pseudocapacitance during constant current charge/discharge cycling. Modification of high surface area carbon black electrodes with GRs yields capacitances of 950–1890 F g−1, power densities >40 W g−1, and minimal change in capacitance during 1500 charge/discharge cycles at 20 A g−1. A capacitance of 1890 F g−1 affords an energy density of 318 Wh kg−1 operating at 1.1 V and 590 Wh kg−1 at 1.5 V. The projected energy density of a hybrid GR/carbon supercapacitor greatly exceeds the current 10 Wh kg−1 for commercial supercapacitors and approaches that of lithium ion batteries.
Gradient‐Distributed Metal–Organic Framework–Based Porous Membranes for Nonaqueous Redox Flow Batteries
Authors: Peng Sangshan , Zhang Leyuan , Zhang Changkun , Ding Yu , Guo Xuelin , He Gaohong , Yu Guihua
Published: October 2018

Nonaqueous redox flow batteries (RFBs) have received significant research interest, but the lack of promising separators with advanced performance seriously hinders the development of nonaqueous RFBs. Here, a robust yet flexible membrane with enhanced selectivity for nonaqueous RFBs is designed via in situ synthesis of metal–organic frameworks (MOFs) in a porous polymeric membrane (Celgard) with a gradient density. The crossover of active species is mitigated by the reduced effective pore size while high ionic conductivity is maintained, which is attributed to the 3D channel structure of MOFs and their gradient distribution in the membrane. A Li/ferrocene RFB with the MOF‐imbedded membrane delivers an excellent high‐rate capability and enhanced cycling stability. The discharge capacity reaches as high as ≈94% of theoretical value at a current density of 4 mA cm−2, and maintains 76% even at 12 mA cm−2. Moreover, a much slower capacity decay rate is achieved (0.09% per cycle over 300 cycles) by using the composite membrane compared with the pristine Celgard membrane (0.24% per cycle). The demonstrated strategy provides new insight into rational design and fabrication of size‐sieving separators for RFBs and can promote further research of MOFs' capability in energy storage.
A Theory‐based Didactic Offering Physicians a Method for Learning and Teaching Others About Human Trafficking
Authors: Cole Michael A. , Daniel Michelle , Chisolm‐Straker Makini , Macias‐Konstantopoulos Wendy , Alter Harrison , Stoklosa Hanni
Published: October 2018

Emergency clinicians are on the frontlines of identifying and caring for trafficked persons. However, most emergency providers have never received training on trafficking, and studies report a significant knowledge gap involving this important topic. Workshops often employ a “train‐the‐trainer” model to address clinicians’ knowledge gaps involving various topics (including trafficking). By offering participants knowledge and skills needed to both understand relevant content and teach this content to future learners, this model aims at promoting widespread dissemination of essential information. However, current train‐the‐trainer workshops typically involve full or multiday sessions and employ multimodal instructional techniques, making them time and resource intensive for both participants and facilitators.

To address these challenges, we created a 50‐minute train‐the‐trainer workshop to teach emergency clinicians the knowledge and skills needed to recognize and care for trafficked patients while providing instructional techniques to teach learners this content in the clinical environment. Learning theory and principles informed the choice of instructional methods and were employed when designing the paper‐based learning guides that functioned as this intervention's primary instructional resource. Guides contained detailed scripts used to perform role‐playing exercises. These “scripted guides” were designed for participants to learn important content while simultaneously practicing techniques to teach this content to one another. They provided the scaffolding necessary to independently direct learning during the workshop (with minimal facilitator intervention), while also being carefully formatted and organized to create an accessible tool for future use during clinical teaching.

The session was implemented at the 2018 Society for Academic Emergency Medicine Annual Meeting in Indianapolis, Indiana. Based on participants’ self‐assessment using a retrospective pre–post test, the workshop was successful in creating a train‐the‐trainer model that is brief, requiring minimal facilitator resources and offers instruction on both content knowledge and instructional methods to disseminate this knowledge to future learners.
The use of new‐media marketing in the green industry: Analysis of social media use and impact on sales
Authors: Yao Becatien , Shanoyan Aleksan , Peterson Hikaru Hanawa , Boyer Cheryl , Baker Lauri
Published: October 2018

During the recession, the decline in home value and home ownership reduced the demand for ornamental plants, lawn and garden products, and related services, which resulted in significantly negative effect on the green industry revenues. Postrecession consolidation in the United States green industry has forced smaller firms to re‐evaluate their marketing strategies. New‐media marketing has gained attention as a relatively low‐cost and high‐exposure marketing strategy. This paper utilizes binary logit and interval censored regression to examine the use and the impact of social‐media marketing in the green industry. The analysis was based on primary data from a survey of US nurseries and garden centers. The findings reveal that the daily use of social‐media marketing is largely driven by the network effect and the managers’ attitudes. They also indicate that the small‐sized firms receive higher returns from social media use in terms of increased sales compared with larger firms.
Monocot plastid phylogenomics, timeline, net rates of species diversification, the power of multi‐gene analyses, and a functional model for the origin of monocots
Authors: Givnish Thomas J. , Zuluaga Alejandro , Spalink Daniel , Soto Gomez Marybel , Lam Vivienne K. Y. , Saarela Jeffrey M. , Sass Chodon , Iles William J. D. , de Sousa Danilo José Lima , Leebens‐Mack James , Chris Pires J. , Zomlefer Wendy B. , Gandolfo Maria A. , Davis Jerrold I. , Stevenson Dennis W. , dePamphilis Claude , Specht Chelsea D. , Graham Sean W. , Barrett Craig F. , Ané Cécile
Published: October 2018

Premise of the Study

We present the first plastome phylogeny encompassing all 77 monocot families, estimate branch support, and infer monocot‐wide divergence times and rates of species diversification.

Methods

We conducted maximum likelihood analyses of phylogeny and BAMM studies of diversification rates based on 77 plastid genes across 545 monocots and 22 outgroups. We quantified how branch support and ascertainment vary with gene number, branch length, and branch depth.

Key Results

Phylogenomic analyses shift the placement of 16 families in relation to earlier studies based on four plastid genes, add seven families, date the divergence between monocots and eudicots+Ceratophyllum at 136 Mya, successfully place all mycoheterotrophic taxa examined, and support recognizing Taccaceae and Thismiaceae as separate families and Arecales and Dasypogonales as separate orders. Only 45% of interfamilial divergences occurred after the Cretaceous. Net species diversification underwent four large‐scale accelerations in PACMAD‐BOP Poaceae, Asparagales sister to Doryanthaceae, Orchidoideae‐Epidendroideae, and Araceae sister to Lemnoideae, each associated with specific ecological/morphological shifts. Branch ascertainment and support across monocots increase with gene number and branch length, and decrease with relative branch depth. Analysis of entire plastomes in Zingiberales quantifies the importance of non‐coding regions in identifying and supporting short, deep branches.

Conclusions

We provide the first resolved, well‐supported monocot phylogeny and timeline spanning all families, and quantify the significant contribution of plastome‐scale data to resolving short, deep branches. We outline a new functional model for the evolution of monocots and their diagnostic morphological traits from submersed aquatic ancestors, supported by convergent evolution of many of these traits in aquatic Hydatellaceae (Nymphaeales).