bluuebunny/crossref_metadata_2025_split huggingface dataset:
Light‐Induced Reversible Control of Ferroelectric Polarization in BiFeO3
Authors: Yang Ming‐Min , Alexe Marin 
Published: February 2018

AbstractManipulation of ferroic order parameters, namely (anti‐)ferromagnetic, ferroelectric, and ferroelastic, by light at room temperature is a fascinating topic in modern solid‐state physics due to potential cross‐fertilization in research fields that are largely decoupled. Here, full optical control, that is, reversible switching, of the ferroelectric/ferroelastic domains in BiFeO3 thin films at room temperature by the mediation of the tip‐enhanced photovoltaic effect is demonstrated. The enhanced short‐circuit photocurrent density at the tip contact area generates a local electric field well exceeding the coercive field, enabling ferroelectric polarization switching. Interestingly, by tailoring the photocurrent direction, via either tuning the illumination geometry or simply rotating the light polarization, full control of the ferroelectric polarization is achieved. The finding offers a new insight into the interactions between light and ferroic orders, enabling fully optical control of all the ferroic orders at room temperature and providing guidance to design novel optoferroic devices for data storage and sensing.
Imaging Heterogeneously Distributed Photo‐Active Traps in Perovskite Single Crystals
Authors: Yuan Haifeng , Debroye Elke , Bladt Eva , Lu Gang , Keshavarz Masoumeh , Janssen Kris P. F. , Roeffaers Maarten B. J. , Bals Sara , Sargent Edward H. , Hofkens Johan 
Published: February 2018

AbstractOrganic–inorganic halide perovskites (OIHPs) have demonstrated outstanding energy conversion efficiency in solar cells and light‐emitting devices. In spite of intensive developments in both materials and devices, electronic traps and defects that significantly affect their device properties remain under‐investigated. Particularly, it remains challenging to identify and to resolve traps individually at the nanoscopic scale. Here, photo‐active traps (PATs) are mapped over OIHP nanocrystal morphology of different crystallinity by means of correlative optical differential super‐resolution localization microscopy (Δ‐SRLM) and electron microscopy. Stochastic and monolithic photoluminescence intermittency due to individual PATs is observed on monocrystalline and polycrystalline OIHP nanocrystals. Δ‐SRLM reveals a heterogeneous PAT distribution across nanocrystals and determines the PAT density to be 1.3 × 1014 and 8 × 1013 cm−3 for polycrystalline and for monocrystalline nanocrystals, respectively. The higher PAT density in polycrystalline nanocrystals is likely related to an increased defect density. Moreover, monocrystalline nanocrystals that are prepared in an oxygen‐ and moisture‐free environment show a similar PAT density as that prepared at ambient conditions, excluding oxygen or moisture as chief causes of PATs. Hence, it is concluded that the PATs come from inherent structural defects in the material, which suggests that the PAT density can be reduced by improving crystalline quality of the material.
Zwitterionic Nanocages Overcome the Efficacy Loss of Biologic Drugs
Authors: Li Bowen , Yuan Zhefan , Zhang Peng , Sinclair Andrew , Jain Priyesh , Wu Kan , Tsao Caroline , Xie Jingyi , Hung Hsiang‐Chieh , Lin Xiaojie , Bai Tao , Jiang Shaoyi 
Published: February 2018

AbstractFor biotherapeutics that require multiple administrations to fully cure diseases, the induction of undesirable immune response is one common cause for the failure of their treatment. Covalent binding of hydrophilic polymers to proteins is commonly employed to mitigate potential immune responses. However, while this technique is proved to partially reduce the antibodies (Abs) reactive to proteins, it may induce Abs toward their associated polymers and thus result in the loss of efficacy. Zwitterionic poly(carboxybetaine) (PCB) is recently shown to improve the immunologic properties of proteins without inducing any antipolymer Abs against itself. However, it is unclear if the improved immunologic profiles can translate to better clinical outcomes since improved immunogenicity cannot directly reflect amelioration in efficacy. Here, a PCB nanocage (PCB NC) is developed, which can physically encase proteins while keeping their structure intact. PCB NC encapsulation of uricase, a highly immunogenic enzyme, is demonstrated to eradicate all the immune responses. To bridge the gap between immunogenicity and efficacy studies, the therapeutic performance of PCB NC uricase is evaluated and compared with its PEGylated counterpart in a clinical‐mimicking gouty rat model to determine any loss of efficacy evoked after five administrations.
A Novel Soft Actuator for the Musculoskeletal System
Authors: Wu Lianjun , Chauhan Indrajeet , Tadesse Yonas 
Published: February 2018

AbstractThe musculoskeletal system (MS) is essential for the movements of biological systems. Inspired by this natural structure, several attempts are made to create a synthetic MS. However, one of the challenges in developing an artificial MS for biomimetic robots is the lack of a high‐performance, low‐cost, light‐weight, and compact artificial muscle. In this Communication, a novel twisted and coiled artificial muscle is demonstrated, which is a promising actuator for the development of the artificial MS. The new muscle is made by twisting a nylon 6 fishing line precursor fiber and wrapping with a very thin (80 µm diameter) resistance wire. The resistance wire is not twisted during twist insertion of the polymer, which is very important for the performance of the muscle. The new muscle termed is integrated in a 3D printed ball‐and‐socket‐based artificial MS. Characterization results show a remarkable tensile actuation (53% strain provided at 1.69 MPa for an input current of 0.22 A). Furthermore, a bioinspired design and fabrication of the synthetic MS is illustrated incorporating antagonistic pairs capable of reaching a bending angle of 20° within 1 s. These actuators can potentially be used in other soft robots, prosthetics, and orthotics advancing the progress in the area.
Stretchable and Tailorable Triboelectric Nanogenerator Constructed by Nanofibrous Membrane for Energy Harvesting and Self‐Powered Biomechanical Monitoring
Authors: Yin Yingying , Wang Jiaona , Zhao Shuyu , Fan Wei , Zhang Xiuling , Zhang Chi , Xing Yi , Li Congju 
Published: February 2018

AbstractWearable triboelectric nanogenerators (TENGs) with both functionality and comfort have become an appealing field of research for portable electronic devices recently. Here, a breathable, stretchable, and tailorable TENG that enables both energy harvesting and biomechanical monitoring is designed. Two layers of nanofiber membranes, which consist of polyvinylidene fluoride supported by conducting fabric and thermoplastic polyurethanes (TPU) supported by Ag elastic fabric, are welded into arch structures through ultrasonic welding technique. As the bottom layer of the arch, the TPU/Ag layer with consistent stretchability guarantees the stretchable of the TENG. Therefore, the TENG can collect various types of irregular movements, such as stretching, pressing, and twisting motions, even the combination of the above all motions. Under twisting stretch, the open‐circuit voltage and short‐circuit current of one basic unit can reach up to 170 V and 4.5 µA, respectively. Besides, the welded TENG is tailorable and it still maintains certain output even if it is partially cut or damaged. The continuous arch‐structured TENGs can also be used as self‐powered motion sensors to constantly monitor the intensity and frequency of human body movements. Thus, this work opens up a new idea for preparation of wearable TENG with both multifunction and better comfort.
Visualizing the Energy Flow of Tailored Light
Authors: Zannotti Alessandro , Vasiljević Jadranka M. , Timotijević Dejan V. , Jović Savić Dragana M. , Denz Cornelia 
Published: February 2018

AbstractExploiting the energy flow of light fields is an essential key to tailor complex optical multistate spin and orbital angular momentum (OAM) dynamics. With this work, the energy flow is identified and quantified by a novel approach that is based on the symmetry breaking induced by nonlinear light–matter interaction of OAM carrying beams at the example of Mathieu beams, showing transverse invariant intensity distributions. These complex scalar nondiffracting beams exhibit outstanding transverse energy flows on elliptic paths. Although their energy is continuously redistributed during linear propagation in homogeneous media, the beams stay nondiffracting. This approach to visualize the energy flow of light is based on the nonlinear self‐action in a nonlinear crystal. By this, the sensitive equilibrium is perturbed and accumulation of rotating high‐intensity spots is enabled. Intensity distributions on elliptic, chiral paths are demonstrated as a manifestation of the energy flow. Furthermore, the formation of corresponding refractive index modulations that may be implemented as chiral waveguides, is controlled via the beam power and structure size.
High‐Throughput Fabrication of Flexible and Transparent All‐Carbon Nanotube Electronics
Authors: Chen Yong‐Yang , Sun Yun , Zhu Qian‐Bing , Wang Bing‐Wei , Yan Xin , Qiu Song , Li Qing‐Wen , Hou Peng‐Xiang , Liu Chang , Sun Dong‐Ming , Cheng Hui‐Ming 
Published: February 2018

AbstractThis study reports a simple and effective technique for the high‐throughput fabrication of flexible all‐carbon nanotube (CNT) electronics using a photosensitive dry film instead of traditional liquid photoresists. A 10 in. sized photosensitive dry film is laminated onto a flexible substrate by a roll‐to‐roll technology, and a 5 µm pattern resolution of the resulting CNT films is achieved for the construction of flexible and transparent all‐CNT thin‐film transistors (TFTs) and integrated circuits. The fabricated TFTs exhibit a desirable electrical performance including an on–off current ratio of more than 105, a carrier mobility of 33 cm2 V−1 s−1, and a small hysteresis. The standard deviations of on‐current and mobility are, respectively, 5% and 2% of the average value, demonstrating the excellent reproducibility and uniformity of the devices, which allows constructing a large noise margin inverter circuit with a voltage gain of 30. This study indicates that a photosensitive dry film is very promising for the low‐cost, fast, reliable, and scalable fabrication of flexible and transparent CNT‐based integrated circuits, and opens up opportunities for future high‐throughput CNT‐based printed electronics.
Effects of Voltage Biasing on Current Extraction in Perovskite Solar Cells
Authors: Hentz Olivia , Rekemeyer Paul , Gradečak Silvija 
Published: February 2018

AbstractThe recent rapid increase in efficiency of organic–inorganic perovskite solar cells (PSCs) has resulted in a need to develop a clear understanding of their stability and working mechanisms. In particular, it has been suggested that ion migration contributes to the commonly observed hysteresis in the current–voltage measurements of PSCs, but the rate of ion migration and its effects on the electronic properties of PSCs remain to be addressed. In this work, electron‐beam‐induced current (EBIC) is used to directly map changes in local current extraction in organic–inorganic PSCs under applied voltage. By combining EBIC mapping, standard current–voltage measurements, and external quantum efficiency measurements, it is shown that between the two potential roles that point defects play in device enhancement under voltage biasing, the effects caused by defect‐mediated ion migration outweigh the effects from the filling of trap states caused by these defects. Evidence is also provided for ion migration preferentially at local features such as extended defects. The measured timescale of tens of seconds for migration across a full device imply that ion migration contributes indirectly to the electronic capacitance of perovskite devices through interface charging.
Sodium and Sodium‐Ion Batteries: 50 Years of Research
Authors: Delmas Claude 
Published: February 2018

AbstractThis paper gives an overview of the research carried out on sodium batteries in the last 50 years. The discovery of the very high Na+ ion conductivity in β‐Al2O3 opened the way to high‐energy batteries (sodium/sulfur and sodium/NiCl2) for load leveling and electrical vehicles. Then, the liquid electrolyte batteries were considered with intercalation‐based electrodes and lithium and sodium as mobile ions. When Sony proposed the lithium‐ion batteries, most research moved to lithium systems, exhibiting a higher energy density. These are now currently used in electronic devices, hybrid electrical vehicle (HEV) and electrical vehicle (EV). The development of renewable energies, which have an intermittent character, requires very large batteries for frequency regulation and peak production shift. For these stationary applications the most important parameters are the lifetime, the power, the price, and the material availability. Since sodium ion batteries are able to satisfy these criteria, these new material families now concern a large part of the scientific community. This article gives a general introduction and an overview of the research carried out on the materials that are presented in detail, in the articles within this special issue on sodium batteries.
Boosting Fast Sodium Storage of a Large‐Scalable Carbon Anode with an Ultralong Cycle Life
Authors: Qian Ji , Wu Feng , Ye Yusheng , Zhang Menglu , Huang Yongxin , Xing Yi , Qu Wei , Li Li , Chen Renjie 
Published: February 2018

AbstractSodium‐ion batteries (SIBs) are considered to be a promising alternative for large‐scale electricity storage. However, it is urgent to develop new anode materials with superior ultralong cycle life performance at high current rates. Herein, a low‐cost and large‐scalable sulfur‐doped carbon anode material that exhibits the best high‐rate cycle performance and the longest cycle life ever reported for carbon anodes is developed. The material delivers a reversible capacity of 142 mA h g−1 at a current rate up to 10 A g−1. After 10 000 cycles the capacity is remained at 126.5 mA h g−1; 89.1% of the initial value. Density functional theory computations demonstrate that the sulfur‐doped carbon has a strong binding affinity for sodium which promotes sodium storage. Meanwhile, the kinetics analysis identifies the capacitive charge storage as a large contributor to sodium storage, which favors ultrafast storage of sodium ions. These results demonstrate a new way to design carbon‐based SIBs anodes for next‐generation large‐scale electricity storage.
Unassisted Water Splitting Using a GaSbxP(1−x) Photoanode
Authors: Martinez‐Garcia Alejandro , Russell Harry B. , Paxton William , Ravipati Srikanth , Calero‐Barney Sonia , Menon Madhu , Richter Ernst , Young James , Deutsch Todd , Sunkara Mahendra K. 
Published: February 2018

AbstractHere, unbiased water splitting with 2% solar‐to‐hydrogen efficiency under AM 1.5 G illumination using new materials based on GaSb0.03P0.97 alloy is reported. Freestanding GaSbxP1−x is grown using halide vapor phase epitaxy. The native conductivity type of the alloy is modified by silicon doping, resulting in an open‐circuit potential (OCP) of 750 mV, photocurrents of 7 mA cm−2 at 10 sun illumination, and corrosion resistance in an aqueous acidic environment. Alloying GaP with Sb at 3 at% improves the absorption of high‐energy photons above 2.68 eV compared to pure GaP material. Electrochemical Impedance Spectroscopy and illuminated OCP measurements show that the conduction band of GaSbxP1−x is at −0.55 V versus RHE irrespective of the Sb concentration, while photocurrent spectroscopy indicates that only radiation with photon energies greater than 2.68 eV generate mobile and extractable charges, thus suggesting that the higher‐laying conduction bands in the Γ 1 valley of the alloys are responsible for exciton generation.
Carbon Incorporation and Anion Dynamics as Synergistic Drivers for Ultrafast Diffusion in Superionic LiCB11H12 and NaCB11H12
Authors: Dimitrievska Mirjana , Shea Patrick , Kweon Kyoung E. , Bercx Marnik , Varley Joel B. , Tang Wan Si , Skripov Alexander V. , Stavila Vitalie , Udovic Terrence J. , Wood Brandon C. 
Published: February 2018

AbstractThe disordered phases of LiCB11H12 and NaCB11H12 possess superb superionic conductivities that make them suitable as solid electrolytes. In these materials, cation diffusion correlates with high orientational mobilities of the CB11H12− anions; however, the precise relationship has yet to be demonstrated. In this work, ab initio molecular dynamics and quasielastic neutron scattering are combined to probe anion reorientations and their mechanistic connection to cation mobility over a range of timescales and temperatures. It is found that anions do not rotate freely, but rather transition rapidly between orientations defined by the cation sublattice symmetry. The symmetry‐breaking carbon atom in CB11H12− also plays a critical role by perturbing the energy landscape along the instantaneous orientation of the anion dipole, which couples fluctuations in the cation probability density directly to the anion motion. Anion reorientation rates exceed 3 × 1010 s−1, suggesting the underlying energy landscape fluctuates dynamically on diffusion‐relevant timescales. Furthermore, carbon is found to modify the orientational preferences of the anions and aid rotational mobility, creating additional symmetry incompatibilities that inhibit ordering. The results suggest that synergy between the anion reorientational dynamics and the carbon‐modified cation–anion interaction accounts for the higher ionic conductivity in CB11H12− salts compared with B12H122−.
Sub‐3 nm Ultrafine Monolayer Layered Double Hydroxide Nanosheets for Electrochemical Water Oxidation
Authors: Zhao Yufei , Zhang Xin , Jia Xiaodan , Waterhouse Geoffrey I. N. , Shi Run , Zhang Xuerui , Zhan Fei , Tao Ye , Wu Li‐Zhu , Tung Chen‐Ho , O'Hare Dermot , Zhang Tierui 
Published: February 2018

AbstractThis study reports the synthesis of ultrafine NiFe‐layered double hydroxide (NiFe‐LDH) nanosheets, possessing a size range between 1.5 and 3.0 nm with a thickness of 0.6 nm. Abundant metal and oxygen vacancies impart the ultrafine nanosheets with semi‐metallic character, and thus superior charge transfer properties and electrochemical water oxidation performance with overpotentials (η) of 254 mV relative to monolayer LDH nanosheets (η of 280 mV) or bulk LDH materials (η of 320 mV) at 10 mA cm−2. These results are highly encouraging for the future application of ultrafine monolayer LDH nanosheets in electronics, solar cells, and catalysis.
Shifts in gene expression profiles are associated with weak and strong Crassulacean acid metabolism
Authors: Heyduk Karolina , Ray Jeremy N. , Ayyampalayam Saravanaraj , Leebens‐Mack James 
Published: February 2018

Premise of the StudyThe relative ease of high throughput sequencing is facilitating comprehensive phylogenomic and gene expression studies, even for nonmodel groups. To date, however, these two approaches have not been merged; while phylogenomic methods might use transcriptome sequences to resolve relationships, assessment of gene expression patterns in a phylogenetic context is less common. Here we analyzed both carbon assimilation and gene expression patterns of closely related species within the Agavoideae (Asparagaceae) to elucidate changes in gene expression across weak and strong phenotypes for Crassulacean acid metabolism (CAM).MethodsGene expression patterns were compared across four genera: Agave (CAM), which is paraphyletic with Polianthes (weak CAM) and Manfreda (CAM), and Beschorneria (weak CAM). RNA‐sequencing was paired with measures of gas exchange and titratable acidity. Climate niche space was compared across the four lineages to examine abiotic factors and their correlation to CAM.Key ResultsExpression of homologous genes showed both shared and variable patterns in weak and strong CAM species. Network analysis highlights that despite shared expression patterns, highly connected genes differ between weak and strong CAM, implicating shifts in regulatory gene function as key for the evolution of CAM. Variation in carbohydrate metabolism between weak and strong CAM supports the importance of sugar turnovers for CAM physiology.ConclusionsIntegration of phylogenetics and RNA‐sequencing provides a powerful tool to study the evolution of CAM photosynthesis across closely related but photosynthetically variable species. Our findings regarding shared or shifted gene expression and regulation of CAM via carbohydrate metabolism have important implications for efforts to engineer the CAM pathway into C3 food and biofuel crops.
Memory complaints, dementia, and neuropathology in older blacks and whites
Authors: Arvanitakis Zoe , Leurgans Sue E. , Fleischman Debra A. , Schneider Julie A. , Rajan Kumar B. , Pruzin Jeremy J. , Shah Raj C. , Evans Denis A. , Barnes Lisa L. , Bennett David A. 
Published: February 2018

ObjectiveTo determine relationships of memory complaints to cognitive function and decline, incident dementia, and neurodegenerative and other neuropathologies, as well as the population‐attributable risk for dementia in older black and white persons.MethodsA total of 4,015 community‐based persons (28% black; 74% women; mean baseline age = 78 years) were enrolled in 1 of 4 longitudinal cohort studies, and another 2,937 in a population‐based cohort. Memory scores, assessed using 2 questions (5‐point Likert scales) were categorized as complaints present or absent. Global cognition and 5 cognitive domains were derived from annual neuropsychological tests. Dementia was assessed from these tests and additional data. Neuropathologic data were available for 1,350 deceased subjects with brain autopsies. Regression and mixed effects models were used to examine relationships of memory complaints to cognition and neuropathology.ResultsBaseline memory complaints (n = 1,310; 33% of 4,015) were associated with lower cognition and faster decline in all domains (global score estimate = −0.032, standard error = 0.004, p < 0.0001), during a mean follow‐up of 6 (standard deviation = 2) years. Persons with memory complaints had higher dementia risk (hazard ratio = 1.64, 95% confidence interval [CI] = 1.42–1.89) and odds of pathologic Alzheimer disease (odds ratio [OR] = 1.96, 95% CI = 1.51–2.54), neocortical Lewy bodies (OR = 2.47, 95% CI = 1.54–3.96), and other neurodegenerative pathologies. Results for dementia risk were similar among blacks and whites. Among 2,937 older persons in a population‐based cohort with similar data, the population‐attributable risk for incident dementia due to memory complaints was 14.0% (95% CI = 2.6–23.0), and did not vary between the black and white groups.InterpretationMemory complaints are common in older black and white persons, and relate to cognitive decline, dementia risk, and neurodegenerative pathologies. Ann Neurol 2018;83:718–729