bluuebunny/crossref_metadata_2025 huggingface dataset:
Highly Secure Plasmonic Encryption Keys Combined with Upconversion Luminescence Nanocrystals
Authors: Park Kisun , Park Minji , Jang Ho Seong , Park Ji Hun , Kim Jaekyun , Cho Younghak , Han Il Ki , Byun Dongjin , Ko Hyungduk
Published: April 2018

This study proposes a novel and highly secure encryption technology based on plasmonic‐enhanced upconversion luminescence (UCL). The technology can be realized by a disordered plasmonic nanostructure composed of a transferred metal nanoparticle–UC nanocrystals (UCNC)–metal (tMUM) film using the graphene transfer process, in which the metal nanoparticles that formed on the graphene layer are transferred using Scotch tape. The plasmonic tMUM film strongly enhances the UCL by a factor of 200 mainly because of the excitation of the gap plasmon polaritons. Meanwhile, the UCNCs in direct contact with the metal film result in luminescence quenching caused by a nonradiative process. Herein, a highly secure anti‐counterfeit film is developed, which is very hard to duplicate and cannot be reused, using two conflicting features (i.e., emission enhancement and quenching phenomena). The UCL is strongly amplified only when the first (i.e., a random metal nanoparticle array) and second (i.e., UCNCs on a Ag film) codes are very precisely overlapped as designed, thereby generating the originally designed final code. Therefore, our novel high‐level security device is expected to be easily applied to protect and identify genuine products.
Identifying Active Sites of Nitrogen‐Doped Carbon Materials for the CO2 Reduction Reaction
Authors: Liu Song , Yang Hongbin , Huang Xiang , Liu Linghui , Cai Weizheng , Gao Jiajian , Li Xuning , Zhang Tao , Huang Yanqiang , Liu Bin
Published: April 2018

Nitrogen‐doped carbon materials are proposed as promising electrocatalysts for the carbon dioxide reduction reaction (CRR), which is essential for renewable energy conversion and environmental remediation. Unfortunately, the unclear cognition on the CRR active site (or sites) hinders further development of high‐performance electrocatalysts. Herein, a series of 3D nitrogen‐doped graphene nanoribbon networks (N‐GRW) with tunable nitrogen dopants are designed to unravel the site‐dependent CRR activity/selectivity. The N‐GRW catalyst exhibits superior CO2 electrochemical reduction activity, reaching a specific current of 15.4 A gcatalyst−1 with CO Faradaic efficiency of 87.6% at a mild overpotential of 0.49 V. Based on X‐ray photoelectron spectroscopy measurements, it is experimentally demonstrated that the pyridinic N site in N‐GRW serves as the active site for CRR. In addition, the Gibbs free energy calculated by density functional theory further illustrates the pyridinic N as a more favorable site for the CO2 adsorption, *COOH formation, and *CO removal in CO2 reduction.
Lithium Titanate Anode Thin Films for Li‐Ion Solid State Battery Based on Garnets
Authors: Pfenninger Reto , Afyon Semih , Garbayo Iñigo , Struzik Michal , Rupp Jennifer L. M.
Published: April 2018

Solid state electrolytes, such as Li‐Garnets, are fastest Li‐ionic conductor materials that have attracted attention for safe hybrid and full solid state battery architectures. Turning to oxide‐based low voltage anodes gives opportunities to avoid Li‐dendrite formation and also to reach full thin film microbattery architectures based on garnets as high energy density replacement for supercapacitors. Herein, it is demonstrated that Li4Ti5O12 thin films deposited by pulsed laser deposition can show stable structures and cycling kinetics reaching almost close to theoretical capacity of 175 mAh g−1 when combined to Li6.25Al0.25La3Zr2O12 pellets. Stable operation at room temperature with 90% of theoretical capacity retention at 2.5 mA g−1 over 22 cycles is achieved on bilayer half cell batteries. Rate capability studies show promising charge and discharge capacities and act as a case study for the well‐known Li4Ti5O12 thin film anode, demonstrating its good compatibility with the investigated solid garnet electrolyte. This gives new perspective on the use of oxide‐based low voltage anodes for future strategies avoiding Li‐dendrite formation or safe solid state microbattery thin film assemblies based on Li‐garnets.
An Injectable Supramolecular Polymer Nanocomposite Hydrogel for Prevention of Breast Cancer Recurrence with Theranostic and Mammoplastic Functions
Authors: Wu Yuanhao , Wang Hongbo , Gao Fei , Xu Ziyang , Dai Fengying , Liu Wenguang
Published: April 2018

The high locoregional breast cancer recurrence rate poses a significant risk for patients' survival. Injecting theranostic drugs‐laden soft tissue‐like hydrogels into the resected breast cavity is a promising strategy to achieve both precisely local therapy of breast cancer and reconstructive mammoplasty. In this work, a robust injectable thermoresponsive supramolecular poly(N‐acryloyl glycinamide‐co‐acrylamide) (PNAm) hydrogel bearing polydopamine (PDA) coated‐gold nanoparticles (AuNPs) and doxorubicin (DOX) is fabricated. The supramolecular polymer nanocomposite (SPN) hydrogels exhibit an excellent photothermal effect arising from PDA‐AuNPs that are tightly fixed to the hydrogel matrix via PDA and amide moieties in the network, built‐in near infrared (NIR) light‐triggered gel–sol transition as well as tunable drug delivery. The PNAm‐PDAAu‐DOX sol driven by prior heating is injected into the cavity of resected cancerous breasts of rats where gelation occurred rapidly while the temperature decreased to body temperature, thereby finely serving as a breast filler. During 4 week of implantation, interval NIR light irradiation can mediate photothermal effect and concertedly controllable DOX release, thus collectively preventing the recurrence of breast cancer. Remarkably, this stable remoldable SPN hydrogel facilitates the breast reconstruction and can be tracked by computed tomography (CT) imaging owing to the intrinsic X‐ray attenuation property of the loaded AuNPs.
Advances in Controlling Differentiation of Adult Stem Cells for Peripheral Nerve Regeneration
Authors: Uz Metin , Das Suprem R. , Ding Shaowei , Sakaguchi Donald S. , Claussen Jonathan C. , Mallapragada Surya K.
Published: April 2018

Adult stems cells, possessing the ability to grow, migrate, proliferate, and transdifferentiate into various specific phenotypes, constitute a great asset for peripheral nerve regeneration. Adult stem cells' ability to undergo transdifferentiation is sensitive to various cell‐to‐cell interactions and external stimuli involving interactions with physical, mechanical, and chemical cues within their microenvironment. Various studies have employed different techniques for transdifferentiating adult stem cells from distinct sources into specific lineages (e.g., glial cells and neurons). These techniques include chemical and/or electrical induction as well as cell‐to‐cell interactions via co‐culture along with the use of various 3D conduit/scaffold designs. Such scaffolds consist of unique materials that possess controllable physical/mechanical properties mimicking cells' natural extracellular matrix. However, current limitations regarding non‐scalable transdifferentiation protocols, fate commitment of transdifferentiated stem cells, and conduit/scaffold design have required new strategies for effective stem cells transdifferentiation and implantation. In this progress report, a comprehensive review of recent advances in the transdifferentiation of adult stem cells via different approaches along with multifunctional conduit/scaffolds designs is presented for peripheral nerve regeneration. Potential cellular mechanisms and signaling pathways associated with differentiation are also included. The discussion with current challenges in the field and an outlook toward future research directions is concluded.
Metal–Organic Frameworks for Water Harvesting from Air
Authors: Kalmutzki Markus J. , Diercks Christian S. , Yaghi Omar M.
Published: April 2018

Water harvesting from air in passive, adsorption‐based devices holds great potential for delivering drinking water to arid regions of the world. This technology requires adsorbents that can be tailored for a maximum working capacity, temperature response, and the relative pressure range in which reversible adsorption occurs. In this respect, metal–organic frameworks (MOFs) are promising, owing to their structural diversity and the precision of their functionalization for adjusting both pore size and hydrophilicity, thereby facilitating the rational design of their water‐sorption characteristics. Here, chemical and structural factors crucial for the design of hydrolytically stable MOFs for water adsorption are discussed. Prevalent water adsorption mechanisms in micro‐ and mesoporous MOFs alongside strategies for fine‐tuning of their adsorption behavior by means of reticular chemistry are presented. Finally, an approach for the selection of promising MOFs with respect to water harvesting from air is proposed and design concepts for next‐generation MOFs for application in passive adsorption‐based water‐harvesting devices are outlined.
Cephalopod‐Derived Biopolymers for Ionic and Protonic Transistors
Authors: Kautz Rylan , Ordinario David D. , Tyagi Vivek , Patel Priyam , Nguyen Tam N. , Gorodetsky Alon A.
Published: April 2018

Cephalopods (e.g., squid, octopuses, and cuttlefish) have long fascinated scientists and the general public alike due to their complex behavioral characteristics and remarkable camouflage abilities. As such, these animals are explored as model systems in neuroscience and represent a well‐known commercial resource. Herein, selected literature examples related to the electrical properties of cephalopod‐derived biopolymers (eumelanins, chitosans, and reflectins) and to the use of these materials in voltage‐gated devices (i.e., transistors) are highlighted. Moreover, some potential future directions and challenges in this area are described, with the aim of inspiring additional research effort on ionic and protonic transistors from cephalopod‐derived biopolymers.
Shape‐Controlled Synthesis of Colloidal Metal Nanocrystals by Replicating the Surface Atomic Structure on the Seed
Authors: Gilroy Kyle D. , Yang Xuan , Xie Shuifen , Zhao Ming , Qin Dong , Xia Younan
Published: April 2018

Controlling the surface structure of metal nanocrystals while maximizing the utilization efficiency of the atoms is a subject of great importance. An emerging strategy that has captured the attention of many research groups involves the conformal deposition of one metal as an ultrathin shell (typically 1–6 atomic layers) onto the surface of a seed made of another metal and covered by a set of well‐defined facets. This approach forces the deposited metal to faithfully replicate the surface atomic structure of the seed while at the same time serving to minimize the usage of the deposited metal. Here, the recent progress in this area is discussed and analyzed by focusing on the synthetic and mechanistic requisites necessary for achieving surface atomic replication of precious metals. Other related methods are discussed, including the one‐pot synthesis, electrochemical deposition, and skin‐layer formation through thermal annealing. To close, some of the synergies that arise when the thickness of the deposited shell is decreased controllably down to a few atomic layers are highlighted, along with how the control of thickness can be used to uncover the optimal physicochemical properties necessary for boosting the performance toward a range of catalytic reactions.
Photocatalytic Hybrid Semiconductor–Metal Nanoparticles; from Synergistic Properties to Emerging Applications
Authors: Waiskopf Nir , Ben‐Shahar Yuval , Banin Uri
Published: April 2018

Hybrid semiconductor–metal nanoparticles (HNPs) manifest unique combined and often synergetic properties stemming from the materials combination. These structures exhibit spatial charge separation across the semiconductor–metal junction upon light absorption, enabling their use as photocatalysts. So far, the main impetus of photocatalysis research in HNPs addresses their functionality in solar fuel generation. Recently, it was discovered that HNPs are functional in efficient photocatalytic generation of reactive oxygen species (ROS). This has opened the path for their implementation in diverse biomedical and industrial applications where high spatially temporally resolved ROS formation is essential. Here, the latest studies on the synergistic characteristics of HNPs are summarized, including their optical, electrical, and chemical properties and their photocatalytic function in the field of solar fuel generation is briefly discussed. Recent studies are then focused concerning photocatalytic ROS formation with HNPs under aerobic conditions. The emergent applications of this capacity are then highlighted, including light‐induced modulation of enzymatic activity, photodynamic therapy, antifouling, wound healing, and as novel photoinitiators for 3D‐printing. The superb photophysical and photocatalytic properties of HNPs offer already clear advantages for their utility in scenarios requiring on‐demand light‐induced radical formation and the full potential of HNPs in this context is yet to be revealed.
PD‐1 Blockade Cellular Vesicles for Cancer Immunotherapy
Authors: Zhang Xudong , Wang Chao , Wang Jinqiang , Hu Quanyin , Langworthy Benjamin , Ye Yanqi , Sun Wujin , Lin Jing , Wang Tianfu , Fine Jason , Cheng Hao , Dotti Gianpietro , Huang Peng , Gu Zhen
Published: April 2018

Cancer cells resist to the host immune antitumor response via multiple suppressive mechanisms, including the overexpression of PD‐L1 that exhausts antigen‐specific CD8+ T cells through PD‐1 receptors. Checkpoint blockade antibodies against PD‐1 or PD‐L1 have shown unprecedented clinical responses. However, limited host response rate underlines the need to develop alternative engineering approaches. Here, engineered cellular nanovesicles (NVs) presenting PD‐1 receptors on their membranes, which enhance antitumor responses by disrupting the PD‐1/PD‐L1 immune inhibitory axis, are reported. PD‐1 NVs exhibit a long circulation and can bind to the PD‐L1 on melanoma cancer cells. Furthermore, 1‐methyl‐tryptophan, an inhibitor of indoleamine 2,3‐dioxygenase can be loaded into the PD‐1 NVs to synergistically disrupt another immune tolerance pathway in the tumor microenvironment. Additionally, PD‐1 NVs remarkably increase the density of CD8+ tumor infiltrating lymphocytes in the tumor margin, which directly drive tumor regression.
Desktop‐Stereolithography 3D‐Printing of a Poly(dimethylsiloxane)‐Based Material with Sylgard‐184 Properties
Authors: Bhattacharjee Nirveek , Parra‐Cabrera Cesar , Kim Yong Tae , Kuo Alexandra P. , Folch Albert
Published: April 2018

The advantageous physiochemical properties of poly(dimethylsiloxane) (PDMS) have made it an extremely useful material for prototyping in various technological, scientific, and clinical areas. However, PDMS molding is a manual procedure and requires tedious assembly steps, especially for 3D designs, thereby limiting its access and usability. On the other hand, automated digital manufacturing processes such as stereolithography (SL) enable true 3D design and fabrication. Here the formulation, characterization, and SL application of a 3D‐printable PDMS resin (3DP‐PDMS) based on commercially available PDMS‐methacrylate macromers, a high‐efficiency photoinitiator and a high‐absorbance photosensitizer, is reported. Using a desktop SL‐printer, optically transparent submillimeter structures and microfluidic channels are demonstrated. An optimized blend of PDMS‐methacrylate macromers is also used to SL‐print structures with mechanical properties similar to conventional thermally cured PDMS (Sylgard‐184). Furthermore, it is shown that SL‐printed 3DP‐PDMS substrates can be rendered suitable for mammalian cell culture. The 3DP‐PDMS resin enables assembly‐free, automated, digital manufacturing of PDMS, which should facilitate the prototyping of devices for microfluidics, organ‐on‐chip platforms, soft robotics, flexible electronics, and sensors, among others.
Localizing Seizure Activity in the Brain Using Implantable Micro‐LEDs with Quantum Dot Downconversion
Authors: Choi Christopher , Colón‐Berríos Aida R. , Hamachi Leslie S. , Owen Jonathan S. , Schwartz Theodore H. , Ma Hongtao , Kymissis Ioannis
Published: April 2018

Current methods for high resolution imaging of neural activity, such as functional magnetic resonance imaging and penetrating electrode arrays, are not well suited for chronic patient monitoring in clinical settings. The ability to locally monitor neural activity in the brain would benefit doctors and surgeons treating and diagnosing neurological diseases such as epilepsy. Measurement of the intrinsic optical signal offers a high resolution (better than 100 µm) for the localization of brain activity. The localized detection of seizures in rats using an implantable optical sensor is demonstrated. The implantable optical sensor is fabricated on a 25 µm thick, flexible polyimide substrate and uses micro‐LEDs to measure localized changes in reflectivity due to cerebral blood flow when attached to the surface of the brain. Quantum dot coatings are applied directly to the micro‐LEDs via pneumatic printing for wavelength conversion by photoluminescent re‐emission.
Highly Flexible, Large‐Area, and Facile Textile‐Based Hybrid Nanogenerator with Cascaded Piezoelectric and Triboelectric Units for Mechanical Energy Harvesting
Authors: Song Jian , Yang Bao , Zeng Wei , Peng Zehua , Lin Shuping , Li Jun , Tao Xiaoming
Published: April 2018

Despite of the rapid development and demonstrations of wearable energy harvesting devices, their industrial applications are limited by the lack of highly flexible, scalable, and facile fabrication methods. Especially, few studies have combined theoretical analysis with the relevant experimental verification. To this end, a highly flexible and large‐area textile‐based hybrid nanogenerator integrated a net‐shaped nanofiber reinforced piezoelectric unit and a triboelectric unit with a microstructured surface configuration is demonstrated. Electrospinning is used to fabricate an optimized Polyvinylidenefluoride (PVDF)‐carbon nanotube (CNT)‐BaTiO3 nanofiber/particle nonwoven fabric of 18 cm × 27 cm for the piezoelectric unit without further polarization. Then a large‐area freestanding Polydimethylsiloxane (PDMS)‐multiwall CNT‐graphite flexible composite film of 20 cm × 25 cm, optimized for the triboelectric unit is prepared by the doctor‐blading method. The resultant hybrid nanogenerator, 4.5 cm × 5 cm in size, generates a rectified average peak output voltage of 161.66 V, along with the highest peak power output of 2.22 W m−2, directly driving 150 light‐emitting diodes (LEDs). Importantly, an explicit theoretical model for the hybrid nanogenerator is proposed and good agreements are obtained between the theoretical and the corresponding experimental results, which shed new light on the mechanism and predict ways to optimize such hybrid nanogenerators.
Hybridized Nanogenerators for Harvesting Vibrational Energy by Triboelectric–Piezoelectric–Electromagnetic Effects
Authors: Du Xinyu , Zhao Shuyu , Xing Yi , Li Nianwu , Wang Jiaona , Zhang Xiuling , Cao Ran , Liu Yuebo , Yuan Zuqing , Yin Yingying , Wang Zhong Lin , Li Congju
Published: April 2018

Harvesting and utilizing the wasted ambient environmental energy can be a feasible solution for continuous operation of distributed sensors that require sustainable power sources. Vibrational mechanical energy is the most ubiquitous energy source in the environment. Therefore, it is important to develop a method to efficiently collect vibrational energy. Here, a hybridized nanogenerator based on triboelectric–piezoelectric–electromagnetic effects for the highly efficient conversion of vibrational mechanical energy into electricity is reported. Integrating with transformers and rectifiers, the hybridized nanogenerator can deliver a power density up to 100 W m−3. Through a power management circuit integrated into the hybridized nanogenerator, a continuous direct current (DC) output is achieved, providing sufficient DC power for driving a radio‐frequency wireless tire‐pressure monitoring system and other conventional electronics. This work takes a significant step toward ubiquitous vibrational energy harvesting and its potential applications in self‐powered wireless sensor networks.
Nanoscale Optical Trapping: A Review
Authors: Bradac Carlo
Published: April 2018

Optical trapping is the craft of manipulating objects with light. Decades after its first inception in 1970, the technique has become a powerful tool for ultracold‐atom physics and manipulation of micron‐sized particles. Yet, optical trapping of objects at the intermediate—nanoscale—range is still beyond full grasp. This matters because the nanometric realm is where several promising advances, from mastering single‐molecule experiments in biology, to fabricating hybrid devices for nanoelectronics and photonics, as well as testing fundamental quantum phenomena in optomechanics, are anticipated to produce impactful breakthroughs. After a comprehensive, theoretical introduction to the phenomenon of optical trapping, this review delves into assessing the current state‐of‐the‐art for optical manipulation of objects at the nanoscale. Emphasis is put on presenting the challenges that coalesced into driving the field to its current development, as well as discussing the outstanding barriers, which might lead to future advancements in the field.
Towards a Sequential One‐Pot Preparation of 1,2,3‐Benzotriazin‐4(3H)‐ones Employing a Key Cp*Co(III)‐catalyzed C−H Amidation Step
Authors: Chirila Paula G. , Skibinski Lauren , Miller Keith , Hamilton Alex , Whiteoak Christopher J.
Published: April 2018

1,2,3‐benzotriazin‐4(3H)‐one derivatives have been recognised for their potential application as pesticides and pharmaceuticals and new methodologies for their preparation, starting from readily accessible reagents would therefore be an attractive proposition. A wide range of differently substituted benzamides are readily available, which provide an excellent substrate scaffold for the application of direct C−H functionalization protocols. In this context, herein we report the use of a Cp*Co(III) catalyst for the amidation of these benzamides, using 1,4,2‐dioxazol‐5‐ones as amidating agent. The isolable intermediate 2‐acetamido benzamide products can thereafter be converted to the desired 1,2,3‐benzotriazin‐4(3H)‐one derivatives through the use of tert‐butyl nitrite under mild conditions. It was found to be possible to perform the second step with the crude reaction mixture obtained from the initial C−H amidation step, leading to the overall development of a facile one‐pot procedure for the preparation of a range of substituted 1,2,3‐benzotriazin‐4(3H)‐one derivatives, requiring only 5 hours of reaction time, which is also applicable on a gram scale. In addition, the key Cp*Co(III)‐catalyzed C−H amidation step has been studied by DFT calculations in order to fully elucidate the mechanism.

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Tailoring TiO2 Nanotube‐Interlaced Graphite Carbon Nitride Nanosheets for Improving Visible‐Light‐Driven Photocatalytic Performance
Authors: Wang Yang , Liu Xueqin , Zheng Cunchuan , Li Yinchang , Jia Songru , Li Zhen , Zhao Yanli
Published: April 2018

Rapid recombination of photoinduced electron–hole pairs is one of the major defects in graphitic carbon nitride (g‐C3N4)‐based photocatalysts. To address this issue, perforated ultralong TiO2 nanotube‐interlaced g‐C3N4 nanosheets (PGCN/TNTs) are prepared via a template‐based process by treating g‐C3N4 and TiO2 nanotubes polymerized hybrids in alkali solution. Shortened migration distance of charge transfer is achieved from perforated PGCN/TNTs on account of cutting redundant g‐C3N4 nanosheets, leading to subdued electron–hole recombination. When PGCN/TNTs are employed as photocatalysts for H2 generation, their in‐plane holes and high hydrophilicity accelerate cross‐plane diffusion to dramatically promote the photocatalytic reaction in kinetics and supply plentiful catalytic active centers. By having these unique features, PGCN/TNTs exhibit superb visible‐light H2‐generation activity of 1364 µmol h−1 g−1 (λ > 400 nm) and a notable quantum yield of 6.32% at 420 nm, which are much higher than that of bulk g‐C3N4 photocatalysts. This study demonstrates an ingenious design to weaken the electron recombination in g‐C3N4 for significantly enhancing its photocatalytic capability.
Room‐Temperature Nanoseconds Spin Relaxation in WTe2 and MoTe2 Thin Films
Authors: Wang Qisheng , Li Jie , Besbas Jean , Hsu Chuang‐Han , Cai Kaiming , Yang Li , Cheng Shuai , Wu Yang , Zhang Wenfeng , Wang Kaiyou , Chang Tay‐Rong , Lin Hsin , Chang Haixin , Yang Hyunsoo
Published: April 2018

The Weyl semimetal WTe2 and MoTe2 show great potential in generating large spin currents since they possess topologically protected spin‐polarized states and can carry a very large current density. In addition, the intrinsic non‐centrosymmetry of WTe2 and MoTe2 endows with a unique property of crystal symmetry‐controlled spin–orbit torques. An important question to be answered for developing spintronic devices is how spins relax in WTe2 and MoTe2. Here, a room‐temperature spin relaxation time of 1.2 ns (0.4 ns) in WTe2 (MoTe2) thin film using the time‐resolved Kerr rotation (TRKR) is reported. Based on ab initio calculation, a mechanism of long‐lived spin polarization resulting from a large spin splitting around the bottom of the conduction band, low electron–hole recombination rate, and suppression of backscattering required by time‐reversal and lattice symmetry operation is identified. In addition, it is found that the spin polarization is firmly pinned along the strong internal out‐of‐plane magnetic field induced by large spin splitting. This work provides an insight into the physical origin of long‐lived spin polarization in Weyl semimetals, which could be useful to manipulate spins for a long time at room temperature.
In Situ One‐Pot Synthesis of MOF–Polydopamine Hybrid Nanogels with Enhanced Photothermal Effect for Targeted Cancer Therapy
Authors: Wang Dongdong , Wu Huihui , Zhou Jiajia , Xu Pengping , Wang Changlai , Shi Ruohong , Wang Haibao , Wang Hui , Guo Zhen , Chen Qianwang
Published: April 2018

Herein, a simple one‐pot way is designed to prepare a type of multifunctional metal–organic framework (MOF)‐based hybrid nanogels by in situ hybridization of dopamine monomer in the skeleton of MnCo. The resultant hybrid nanoparticles (named as MCP) show enhanced photothermal conversion efficiency in comparison with pure polydopamine or MnCo nanoparticles (NPs) synthesized under a similar method and, therefore, show great potential for photothermal therapy (PTT) in vivo. The MCP NPs are expected to possess T
1 positive magnetic resonance imaging ability due to the high‐spin Mn‐N6 (S = 5/2) in the skeleton of MnCo. To improve the therapy efficiency as a PTT agent, the MCP NPs are further modified with functional polyethylene glycol (PEG) and thiol terminal cyclic arginine–glycine–aspartic acid peptide, respectively: the first one is to increase the stability, biocompatibility, and blood circulation time of MCP NPs in vivo; the second one is to increase the tumor accumulation of MCP‐PEG NPs and improve their therapeutic efficiency as photothermal agent.
Room‐Temperature Carbon Nanotube Single‐Electron Transistors with Mechanical Buckling–Defined Quantum Dots
Authors: Zhang Jian , Liu Siyu , Kong Lingyuan , Nshimiyimana Jean Pierre , Hu Xiao , Chi Xiannian , Wu Pei , Liu Jia , Chu Weiguo , Sun Lianfeng
Published: April 2018

Single‐electron transistors (SETs) have been proposed as a future alternative to conventional Si‐based electronics. However, their practical applications are strongly limited because most SETs operate at cryogenic temperatures. In this work, room temperature operating SETs are successfully fabricated with the realization of a mechanical buckling–defined quantum dot within a suspended and strained single‐walled carbon nanotube. Clear Coulomb oscillations are observed at room temperature due to the Coulomb blockade effect. The Coulomb charging energy is calculated to be 160 meV, which substantially exceeds the thermal energy. At 10 K, the Coulomb staircases are observed in the current–voltage characteristics with an energy level separation ≈29 meV, confirming that the island behaves as a well‐defined quantum dot for the electrons. This device fabrication method may also help future investigations into the electromechanical properties of nanotube quantum systems.
Reducing Trap States in Printed Indium Zinc Oxide Transistors by Doping with Benzyl Viologen
Authors: Kim Hyonwoong , Ng Tse Nga
Published: April 2018

An air‐stable, strongly reducing molecule benzyl viologen (BV) is used to induce charge‐transfer doping of the indium zinc oxide semiconductor in inkjet‐printed thin‐film transistors. The device mobility is improved from 5.8 ± 1.4 cm2 V−1 s−1 in the undoped devices and reached up to 8.7 ± 1.0 cm2 V−1 s−1 after BV treatment. Through measurement of frequency‐dependent admittance and capacitance, this work quantifies the density of interface states and shows that interfacial trap density is four times lower in the BV‐doped transistors compared to undoped devices.
Chemical Doping Effects on CVD‐Grown Multilayer MoSe2 Transistor
Authors: Yoo Hocheon , Hong Seongin , Moon Hyunseong , On Sungmin , Ahn Hyungju , Lee Han‐Koo , Kim Sunkook , Hong Young Ki , Kim Jae‐Joon
Published: April 2018

Multilayer transition metal dichalcogenides (TMDs) potentially provide opportunities for large‐area electronics, including flexible displays and wearable sensors. However, most TMDs suffer from a Schottky barrier (SB) and nonuniform defects, which severely limit their electrical performances. Here, a novel chemical doping scheme is presented using poly‐(diketopyrrolopyrrole‐terthiophene) (PDPP3T) to compensate the defects and SB of multilayer molybdenum diselenide (MoSe2), exhibiting greatly enhanced electrical characteristics, including on‐current (≈2000‐fold higher) and photoresponsivity (≈10‐fold larger) over the baseline MoSe2 device. Based on comprehensive analysis using X‐ray photoelectron spectroscopy, grazing incidence wide‐angle X‐ray diffraction, atomic force microscopy, and near‐edge X‐ray absorption of fine structure, it is shown that two mechanisms (dipole‐induced and charge‐transfer doping effects) account for such enhancements in the multilayer MoSe2 device. The methodical generality of the strong n‐doping behavior of multilayer MoSe2 is further demonstrated by applying thiophene instead of PDPP3T.
Effect of Componential Proportion in Bimetallic Electrocatalysts on the Aprotic Lithium‐Oxygen Battery Performance
Authors: Luo Xiangyi , Ge Le , Ma Lu , Kropf Arthur J. , Wen Jianguo , Zuo Xiaobing , Ren Yang , Wu Tianpin , Lu Jun , Amine Khalil
Published: April 2018

Rechargeable lithium‐oxygen (Li‐O2) batteries are one of the most promising technologies for next‐generation energy storage, which is also a critical part of the future renewable energy portfolio; however, its commercialization is still hindered by several challenges. The high charge overpotential, in particular, not only causes problems by increasing the possibility of electrolyte decomposition but also induces a low round‐trip efficiency and coulombic efficiency. Here, by choosing the right component proportion in Pt‐Cu bimetallic electrocatalysts that optimize electrocatalytic activity of electrochemical reactions, especially of oxygen evolution reactions, a superior electrochemical behavior is demonstrated, with a low charge overpotential of 0.2 V and cycleability of 50 discharge/charge cycles before capacity fading. The optimized Pt‐Cu bimetallic electrocatalysts significantly reduce the charge overpotential and furthermore enhance the efficiency, stability, and cycleability of an aprotic Li‐O2 battery.
A Comprehensive Review on Controlling Surface Composition of Pt‐Based Bimetallic Electrocatalysts
Authors: Zhang Bin‐Wei , Yang Hui‐Ling , Wang Yun‐Xiao , Dou Shi‐Xue , Liu Hua‐Kun
Published: April 2018

With increasing energy demands worldwide, significant efforts have been made to develop superior electrocatalysts for efficient energy conversion systems. Among all the electrocatalysts exploited, Pt‐based bimetallic nanomaterials stand out by virtue of their high catalytic activity and relatively low cost due to the introduction of a nonprecious metal component. It should be noted that electrocatalytic reactions only take place on the surface of catalysts, so investigations of the surface composition of Pt‐based bimetallic nanomaterials are necessary for practical electrocatalysts. In this review, recent studies on controlling the surface composition of Pt‐based bimetallic catalysts for the oxygen reduction reaction, formic acid electrooxidation, and ethanol electrooxidation are summarized. The controlling strategies, including the chemical method and the electrochemical method, are discussed. The impacts of surface composition compositions on the electrocatalytic performance are also discussed. Finally, the challenges and future directions for controlling the surface composition of Pt‐based bimetallic nanomaterials are addressed.
The “Midas Touch” Transformation of TiO2 Nanowire Arrays during Visible Light Photoelectrochemical Performance by Carbon/Nitrogen Coimplantation
Authors: Song Xianyin , Li Wenqing , He Dong , Wu Hengyi , Ke Zunjian , Jiang Changzhong , Wang Gongming , Xiao Xiangheng
Published: April 2018

Titanium dioxide is a promising photoanode material for water oxidation, but it is substantially limited by its poor efficiency in the visible light range. Herein, an innovative carbon/nitrogen coimplantation method is utilized to realize the “Midas touch” transformation of TiO2 nanowire (NW) arrays for photoelectrochemical (PEC) water splitting in visible light. These modified golden–yellow rutile TiO2 NW arrays (C/N‐TiO2) exhibit remarkably enhanced absorption in visible light regions and more efficient charge separation and transfer. As a result, the photocurrent density of carbon/nitrogen co‐implanted TiO2 under visible light (>420 nm) can reach 0.76 mA cm−2, which far exceeds the value of 3 µA cm−2 seen for pristine TiO2 nanowire arrays at 0.8 V versus Ag/AgCl. An incident photon to electron conversion efficiency of ≈14.8% is achieved at 450 nm on C/N‐TiO2 without any other cocatalysts. The ion implantation doping approach, combined with codoping strategies, is proved to be an effective strategy for enhancing the photoelectrochemical conversion and can enable further improvement of the PEC water‐splitting performance of many other semiconductor photoelectrodes.
A Thieno[3,2‐c]Isoquinolin‐5(4H)‐One Building Block for Efficient Thick‐Film Solar Cells
Authors: Li Dan , Xiao Zuo , Wang Shizhe , Geng Xinjian , Yang Shangfeng , Fang Junfeng , Yang Huai , Ding Liming
Published: April 2018

An aromatic lactam acceptor unit, thieno[3,2‐c]isoquinolin‐5(4H)‐one (TIQ), is developed. Compared with its analogues, dithieno[3,2‐b:2′,3′‐d]pyridin‐5(4H)‐one (DTP) and phenanthridin‐6(5H)‐one (PN), TIQ shows its advantage in constructing donor–acceptor (D–A) copolymers for efficient solar cells. TIQ‐based D–A copolymer PTIQ4TFBT delivers a power conversion efficiency (PCE) of 10.16% in polymer:fullerene solar cells, while those based on DTP and PN copolymers, PDTP4TFBT and PPN4TFBT, afford PCEs around 8.5%. The higher performance of PTIQ4TFBT:PC71BM solar cells originates from enhanced short‐circuit current density (Jsc) and fill factor (FF), because of favorable morphology, less bimolecular recombination, and balanced charge transport in the active layer. Moreover, the performance for PTIQ4TFBT:PC71BM solar cells is less sensitive to active layer thickness than PDTP4TFBT:PC71BM and PPN4TFBT:PC71BM solar cells. Over 8% PCEs can be obtained from PTIQ4TFBT:PC71BM solar cells when the active layer thickness is over 500 nm.
3D Printing Quasi‐Solid‐State Asymmetric Micro‐Supercapacitors with Ultrahigh Areal Energy Density
Authors: Shen Kai , Ding Junwei , Yang Shubin
Published: April 2018

A 3D printing approach is first developed to fabricate quasi‐solid‐state asymmetric micro‐supercapacitors to simultaneously realize the efficient patterning and ultrahigh areal energy density. Typically, cathode, anode, and electrolyte inks with high viscosities and shear‐thinning rheological behaviors are first prepared and 3D printed individually on the substrates. The 3D printed asymmetric micro‐supercapacitor with interdigitated electrodes exhibits excellent structural integrity, a large areal mass loading of 3.1 mg cm−2, and a wide electrochemical potential window of 1.6 V. Consequently, this 3D printed asymmetric micro‐supercapacitor displays an ultrahigh areal capacitance of 207.9 mF cm−2. More importantly, an areal energy density of 73.9 µWh cm−2 is obtained, superior to most reported interdigitated micro‐supercapacitors. It is believed that the efficient 3D printing strategy can be used to construct various asymmetric micro‐supercapacitors to promote the integration in on‐chip energy storage systems.
Apically Dominant Mechanism for Improving Catalytic Activities of N‐Doped Carbon Nanotube Arrays in Rechargeable Zinc–Air Battery
Authors: Niu Wenhan , Pakhira Srimanta , Marcus Kyle , Li Zhao , Mendoza‐Cortes Jose L. , Yang Yang
Published: April 2018

The oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) in zinc–air batteries (ZABs) require highly efficient, cost‐effective, and stable electrocatalysts as alternatives to high cost and low poison resistant platinum group metals (PGM) catalysts. Although nitrogen‐doped carbon nanotube (NCNT) arrays are now capable of catalyzing ORR efficiently, their hydrophobic surface and base‐growth mode are found to limit the catalytic performance in the practical ZABs. Here, the concept of an apically dominant mechanism in improving the catalytic performance of NCNT by precisely encapsulating CoNi nanoparticles (NPs) within the apical domain of NCNT on the Ni foam (denoted as CoNi@NCNT/NF) is demonstrated. The CoNi@NCNT/NF exhibits a more excellent catalytic performance toward both ORR and OER than that of traditional NCNT derived from the base‐growth method. The ZAB coin cell using CoNi@NCNT/NF as an air electrode shows a peak power density of 127 mW cm−2 with an energy density of 845 Wh kgZn−1 and rechargeability over 90 h, which outperforms the performance of PGM catalysts. Density functional theory calculations reveal that the ORR catalytic performance of the CoNi@NCNT/NF is mainly attributed to the synergetic contributions from NCNT and the apical active sites on NCNT near to CoNi NPs.
Voluntary food labeling: The additive effect of “free from” labels and region of origin
Authors: Grebitus Carola , Peschel Anne O. , Hughner Renée Shaw
Published: April 2018

This study analyzes the effect of voluntary food labeling, with focus on genetically modified organisms (GMO), pesticide usage, and region of origin. We focus on Medjool dates because though U.S. production of this crop has rapidly grown in recent years, no research exists related to consumers’ preferences and WTP for this crop. We conducted online choice experiments with a sample of over 1,400 consumers from the U.S. to determine WTP for production and region of origin labeling accounting for simultaneous versus individual labeling. Results indicate consumers prefer dates grown in Arizona over dates not labeled for region of origin. Also, pesticide‐free and GMO‐free dates are preferred, with pesticide‐free having a larger impact on choices. Furthermore, accounting for interactions between these two labels reveals that they can be considered subadditive in that labeling the product with both designations reduces WTP relative to “pesticide‐free” labeling only. [EconLit citations: M31, Q13]
Estimating bilateral market power of processors and retailers in the U.S. beef industry
Authors: Chung Chanjin , Park Seongjin , Lee Jungmin
Published: April 2018

This paper estimates the full bilateral market power of processors and retailers in the U.S. beef industry. Our full bilateral imperfect competition model allows potential market power exertion from all adjacent upstream and downstream markets of processors and retailers. Empirical results show the presence of market power from processors and retailers in both output and input procurement markets of the U.S. beef industry. Estimates of conjectural elasticities and market power indices suggest that processors’ market power exertion is greater than the exertion of retailers’ market power in the U.S. beef industry. Results of the goodness‐of‐fit statistics indicate that flexible frameworks work better than restrictive models in representing the bilateral market structure. Estimates of market power parameters and market power indices are sensitive to the choice of market structure model as well as functional forms of production function. These findings indicate that any erroneous assumptions on market structure and functional form of production function may result in misleading estimates of market power. [EconLit citations: D43, L11, L13, Q13].
Social capital and the financing performance of farmer cooperatives in Fujian Province, China
Authors: Yu Liyan , Nilsson Jerker
Published: April 2018

Although social capital is commonly believed to affect cooperative financing, empirical results are sparse. Using data from surveys of members of 60 cooperatives in Fujian province, China, this study shows that social capital is related to cooperative financing performance, interpreted as (1) members’ willingness to provide equity, (2) loans from members and from banks, and (3) cooperatives providing financing services to members. Three dimensions of social capital are identified; external, relational, and cognitive. The findings indicate that Chinese cooperatives obtain bank credit more easily if they have been granted government “honors” and if the chairperson has government contacts (external social capital). Loyal members (relational social capital) are more likely to obtain financial services, such as guarantees for member loans. Cooperatively convinced members (cognitive social capital) are more willing to provide capital. [EconLit citations: A13; P13; Q14].
Consumer preferences for aquaponic produce: Implications from an experimental auction
Authors: Short Gianna , Yue Chengyan , Abbey Marie , Anderson Neil , Phelps Nicholas , Venturelli Paul , Vickers Zata
Published: April 2018

Aquaponics is the integration of aquaculture and hydroponics to grow fish and plants together in one system. Many producers in the northern United States are attracted to aquaponics for its potential to produce indoors year‐round. However, little is known about consumer preferences for products grown in aquaponic systems. To address this knowledge gap, we conducted an experimental auction to measure the impact of information about production method on consumers’ willingness‐to‐pay (WTP) for lettuce. For most participants, WTP was similar for both aquaponic and soil grown lettuce with overall average bids of $1.47 per 8 ounces and $1.48 per 8 ounces, respectively. Learning how samples were grown (either aquaponic or soil‐grown) rarely changed bids significantly, although on average, participants with environmental group membership lowered their bids for aquaponic lettuce samples. In general, higher frequency shoppers expressed higher average WTP for all types of lettuce. [Q100 Agriculture: General, Q220 Renewable Resources and Conservation: Fishery; Aquaculture]
Liver resection combined with inferior vena cava resection and reconstruction using artificial vascular graft: A literature review
Authors: Tomimaru Yoshito , Eguchi Hidetoshi , Wada Hiroshi , Doki Yuichiro , Mori Masaki , Nagano Hiroaki
Published: April 2018

In cases where liver tumors invade the inferior vena cava (IVC), IVC resection along with liver resection may be needed to effect a cure. Furthermore, if the IVC defect is large, IVC reconstruction with vascular graft after resection is required. There are limited reports of cases of IVC reconstruction using a graft. By reviewing data from the literature of previous studies, the present study was aimed at investigating the surgical outcomes of liver resection with IVC resection and reconstruction using an artificial vascular graft. PubMed was searched for previous articles reporting cases with the combined surgery. The search was limited to articles in English, and cases with exceptional surgeries such as in situ cold perfusion, and ante situm and ex vivo techniques were excluded from this study. Surgical outcomes of the extracted cases were investigated. Cases dealt only with primary closure after IVC resection, and those in which the IVC tumor thrombus was treated by opening the IVC wall, removing the thrombus and then closing the IVC without wall excision were not included in this study. The literature search identified 13 studies, including 111 cases. Operative mortality in the reported cases was 8.1% (9 out of 111 cases). Thrombus in the artificial vascular graft was observed in two cases, and patency of the graft during the follow‐up period was confirmed in 109 of the 111 cases (98.2%). These results suggested that the surgical outcomes of liver resection combined with IVC resection and reconstruction using the artificial vascular graft were favorable.
Character evolution and missing (morphological) data across Asteridae
Authors: Stull Gregory W. , Schori Melanie , Soltis Douglas E. , Soltis Pamela S.
Published: April 2018

Premise of the Study

Our current understanding of flowering plant phylogeny provides an excellent framework for exploring various aspects of character evolution through comparative analyses. However, attempts to synthesize this phylogenetic framework with extensive morphological data sets have been surprisingly rare. Here, we explore character evolution in Asteridae (asterids), a major angiosperm clade, using an extensive morphological data set and a well‐resolved phylogeny.

Methods

We scored 15 phenotypic characters (spanning chemistry, vegetative anatomy, and floral, fruit, and seed features) across 248 species for ancestral state reconstruction using a phylogenetic framework based on 73 plastid genes and the same 248 species.

Key Results

Iridoid production, unitegmic ovules, and cellular endosperm were all reconstructed as synapomorphic for Asteridae. Sympetaly, long associated with asterids, shows complex patterns of evolution, suggesting it arose several times independently within the clade. Stamens equal in number to the petals is likely a synapomorphy for Gentianidae, a major asterid subclade. Members of Lamianae, a major gentianid subclade, are potentially diagnosed by adnate stamens, unilacunar nodes, and simple perforation plates.

Conclusions

The analyses presented here provide a greatly improved understanding of character evolution across Asteridae, highlighting multiple characters potentially synapomorphic for major clades. However, several important parts of the asterid tree are poorly known for several key phenotypic features (e.g., degree of petal fusion, integument number, nucellus type, endosperm type, iridoid production). Further morphological, anatomical, developmental, and chemical investigations of these poorly known asterids are critical for a more detailed understanding of early asterid evolution.