bluuebunny/crossref_metadata_2025_split huggingface dataset:
Active Thermal Control of 5 nm Gap Terahertz Antennas
Authors: Yun Hyeong Seok , Jeong Jeeyoon , Kim Dasom , Kim Dai‐Sik 
Published: December 2018

AbstractMetallic nanostructures are combined with various active materials for electrical, optical, and thermal modulations of their optical properties. In particular, for the thermal modulation, deformation of metallic nanostructures at high temperatures limits the applications to relatively low temperatures, where thermal expansion of metals is negligible. Here, a unique regime is reported where terahertz (THz) waves transmitting through 5 nm wide slot antennas can be significantly modulated via controlled thermal expansion of metals without active materials. The normalized amplitude is modulated by 20% and the resonant frequency by 22% at an elevated temperature of 150 °C, indicating a decrease in the gap width by 50%. The extreme width‐to‐length ratio of the THz slot antennas compensates the small thermal expansion coefficient of metals, enabling the gap width to be considerably changed. COMSOL simulation and coupled‐mode method (CMM) calculation quantitatively support the experimental data. This works suggests a new possibility of thermally active metallic nanostructures.
Ultrawide‐Bandgap Amorphous MgGaO: Nonequilibrium Growth and Vacuum Ultraviolet Application
Authors: Dong Mei , Zheng Wei , Xu Cunhua , Lin Richeng , Zhang Dan , Zhang Zhaojun , Huang Feng 
Published: December 2018

AbstractNew ultrawide‐bandgap (>6.0 eV) photosensitive materials are in urgent need to meet the requirements of vacuum‐ultraviolet (VUV) photodetection applied in deep space exploration. Here, a nonequilibrium growth method is reported to fabricate amorphous MgGaO (a‐MgGaO) films with an ultrawide bandgap of 6.0 eV and an ultrashort absorption edge of 206 nm by alloying MgO and Ga2O3. By combining the as‐grown films with p‐type graphene (p‐Gr) which serves as a transparent conductor, a vacuum‐ultraviolet photovoltaic detector of p‐Gr/a‐MgGaO/n‐SiC (n‐type SiC) is constructed. The device exhibits an excellent VUV spectral selectivity with a VUV (185 nm)/UV (250 nm) rejection ratio exceeding 103, high photoresponsivity (≈10.3 mA W−1) under 0 V bias, and ultrafast response and recovery time of 1.94 µs and 0.6 ms, respectively. The reported nonequilibrium growth method is expected to have tremendous potential in fabricating ultrawide‐bandgap oxide compounds, and finally facilitate future deep space exploration.
Panchromatic All‐Polymer Photodetector with Tunable Polarization Sensitivity
Authors: Sen Pratik , Yang Ruonan , Rech Jeromy J. , Feng Yuanxiang , Ho Carr Hoi Yi , Huang Jinsong , So Franky , Kline R. Joseph , You Wei , Kudenov Michael W. , O'Connor Brendan T. 
Published: December 2018

AbstractIn this report, a high‐performance all‐polymer organic photodetector that is sensitive to linearly polarized light throughout the visible spectrum is demonstrated. The active layer is a bulk heterojunction composed of an electron donor polymer PBnDT‐FTAZ and acceptor polymer P(NDI2OD‐T2) that have complementary spectral absorption resulting in efficient detection from 350 to 800 nm. The blend film exhibits good ductility with the ability to accommodate large strains of over 60% without fracture. This allows the film to undergo large uniaxial strain resulting in in‐plane alignment of both polymers making the film optically anisotropic and intrinsically polarization sensitive. The films are characterized by UV–vis spectroscopy and grazing incidence wide‐angle X‐ray scattering showing that both polymers have similar in‐plane backbone alignment and maintain packing order after being strained. The films are integrated into devices and characterized under linear polarized light. The strain‐oriented detectors have maximum photocurrent anisotropies of 1.4 under transverse polarized light while maintaining peak responsivities of 0.21 A W−1 and a 3 dB cutoff frequency of ≈1 kHz. The demonstrated performance is comparable to the current state of the art all‐polymer photodetectors with the added capability of polarization sensitivity enabling new application opportunities.
Extended Exposure to Stiff Microenvironments Leads to Persistent Chromatin Remodeling in Human Mesenchymal Stem Cells
Authors: Killaars Anouk R. , Grim Joseph C. , Walker Cierra J. , Hushka Ella A. , Brown Tobin E. , Anseth Kristi S. 
Published: December 2018

AbstractBone marrow derived human mesenchymal stem cells (hMSCs) are a promising cell source for regenerative therapies; however, ex vivo expansion is often required to achieve clinically useful cells numbers. Recent results reveal that when MSCs are cultured in stiff microenvironments, their regenerative capacity can be altered in a manner that is dependent on time (e.g., a mechanical dosing analogous to a chemical one). It is hypothesized that epigenomic modifications are involved in storing these mechanical cues, regulating gene expression, and ultimately leading to a mechanical memory. Using hydrogels containing an allyl sulfide cross‐linker and a radical‐mediated addition‐fragmentation chain transfer process, in situ softened hMSC‐laden hydrogels at different time points are achieved and the effects of short‐term and long‐term mechanical dosing on epigenetic modifications in hMSCs are quantified. Results show that histone acetylation and chromatin organization adapt rapidly after softening and can be reversible or irreversible depending on time of exposure to stiff microenvironments. Furthermore, epigenetic modulators are differentially expressed depending on the culture history. Collectively, these experiments suggest that epigenetic remodeling can be persistent and might be a memory keeper.
Etiology of subjective taste loss
Authors: Hunt Joseph D. , Reiter Evan R. , Costanzo Richard M. 
Published: December 2018

BackgroundTaste complaints are commonly encountered in clinical practice. Although changes in taste function may arise from varied etiologies, numerous other factors may impact patients’ taste perceptions, the most common of which is olfactory dysfunction. Thus, patients with taste complaints may or may not have measurable deficits in taste function. This poses a challenge to providers faced with evaluation of patients with taste disorders, and may delay diagnosis and management.MethodsWe retrospectively examined records of 1108 patients evaluated at the Virginia Commonwealth University Health System Smell and Taste Clinic and compared patients’ subjective taste complaints with results of objective testing of the senses of taste and smell.ResultsA total of 358 patients had a subjective taste complaint and results from both gustatory and olfactory function tests. Patients were grouped by subjective complaint as “taste only” (n = 63) or “taste and smell” (n = 295). Of patients reporting a “taste‐only” complaint, 25.4% had abnormal gustatory function, whereas 44.4% had abnormal olfactory function. For those reporting taste‐and‐smell complaints, only 9.5% had abnormal gustatory function, whereas 86.8% had abnormal olfactory function.ConclusionThis study supports the hypothesis that patients who present with a taste complaint are more likely to have an underlying olfactory than gustatory impairment. However, those with a taste‐only complaint are more likely to have objective gustatory deficits than those with a taste‐and‐smell complaint. These findings may prove useful to healthcare providers who evaluate patients presenting with complaints of taste loss.
Transient Dynamics of Super Bloch Oscillations of a 1D Holstein Polaron under the Influence of an External AC Electric Field
Authors: Huang Zhongkai , Hoshina Masayuki , Ishihara Hajime , Zhao Yang 
Published: December 2018

AbstractTheoretical formalism for DC‐field polaron dynamics is extended to the dynamics of a 1D Holstein polaron in an external AC electric field using multiple Davydov trial states. Effects of carrier–phonon coupling on detuned and resonant scenarios are investigated for both phase and nonzero phase. For slightly off‐resonant or detuned cases, a beat between the usual Bloch oscillations and an AC driving force results in super Bloch oscillations, that is, rescaled Bloch oscillations in both the spatial and the temporal dimension. Super Bloch oscillations are damped by carrier–phonon coupling. For resonant cases, if the carrier is created on two nearest‐neighboring sites, the carrier wave packet spreads with small‐amplitude oscillations. Adding carrier–phonon coupling localizes the carrier wave packet. If an initial broad Gaussian wave packet is adopted, the centroid of the carrier wave packet moves with a certain velocity and with its shape unchanged. Adding carrier–phonon coupling broadens the carrier wave packet and slows down the carrier movement. Our findings may help provide guiding principles on how to manipulate the dynamics of the super Bloch oscillations of carriers in semiconductor superlattice and optical lattices by modifying DC and AC field strengths, AC phases, and detuning parameters.
Hydrogel wound dressings based on chitosan and xyloglucan: Development and characterization
Authors: Martínez‐Ibarra Diana M. , Sánchez‐Machado Dalia I. , López‐Cervantes Jaime , Campas‐Baypoli Olga N. , Sanches‐Silva Ana , Madera‐Santana Tomas J. 
Published: December 2018

ABSTRACTXyloglucan is a polysaccharide isolated from chia seed gum (Salvia hispanica L.) and can act as a soluble fiber. In this investigation, several porous hydrogels were prepared from mixtures of chitosan and xyloglucan. To characterize these biomaterials, their mechanical, hydrophilic, structural, and morphological properties were measured, as well as their biodegradability and antimicrobial activity. The pore sizes of the porous hydrogels were 32.8–101.6 μm, and their water retention capacity is proportional to the added amount of xyloglucan. Dynamic degradation of the porous hydrogels with lysozymes showed progressive weight loss during the 14 days of testing. The mechanical properties improved slightly after the addition of xyloglucan. All of these results indicate that the incorporation of vegetable‐derived polymers such as xyloglucan improves the properties of chitosan without affecting its antimicrobial capacity. Thus, biomaterials based on chitosan and xyloglucan are a promising option for the design of hydrogel wound dressings for medical applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47342.
Hierarchical Nanotubes Constructed by Co9S8/MoS2 Ultrathin Nanosheets Wrapped with Reduced Graphene Oxide for Advanced Lithium Storage
Authors: Liu Yayuan , Geng Hongbo , Ang Edison Huixiang , Cao Xueqin , Zheng Junwei , Gu Hongwei 
Published: December 2018

AbstractNanostructured hybrid metal sulfides have attracted intensive attention due to their fascinating properties that are unattainable by the single‐phased counterpart. Herein, we report an efficient approach to construct cobalt sulfide/molybdenum disulfide (Co9S8/MoS2) wrapped with reduced graphene oxide (rGO). The unique structures constructed by ultrathin nanosheets and synergetic effects benefitting from bimetallic sulfides provide improved lithium ions reaction kinetics, and they retain good structural integrity. Interestingly, the conductive rGO can facilitate electron transfer, increase the electronic conductivity and accommodate the strain during cycling. When evaluated as anode materials for lithium‐ion batteries (LIBs), the resultant reduced graphene oxide‐coated cobalt sulfide/molybdenum disulfide (Co9S8/MoS2@rGO) nanotubes deliver high specific capacities of 1140, 948, 897, 852, 820, 798 and 784 mAh g−1 at the various discharging current densities of 0.2, 0.5, 1, 2, 3, 4 and 5 A g−1, respectively. In addition, they can maintain an excellent cycle stability with a discharge capacity of 807 mAh g−1 at 0.2 A g−1 after 70 cycles, 787 mAh g−1 at 1 A g−1 after 180 cycles and 541 mAh g−1 at 2 A g−1 after 200 cycles. The proposed method may offer fundamental understanding for the rational design of other hybrid functional composites with high Li‐storage properties.
Exploring Potential Energy Surfaces for Aggregation‐Induced Emission—From Solution to Crystal
Authors: Crespo‐Otero Rachel , Li Quansong , Blancafort Lluís 
Published: December 2018

AbstractAggregation‐induced emission (AIE) is a phenomenon where non‐luminescent compounds in solution become strongly luminescent in aggregate and solid phase. It provides a fertile ground for luminescent applications that has rapidly developed in the last 15 years. In this review, we focus on the contributions of theory and computations to understanding the molecular mechanism behind it. Starting from initial models, such as restriction of intramolecular rotations (RIR), and the calculation of non‐radiative rates with Fermi's golden rule (FGR), we center on studies of the global excited‐state potential energy surfaces that have provided the basis for the restricted access to a conical intersection (RACI) model. In this model, which has been shown to apply for a diverse group of AIEgens, the lack of fluorescence in solution comes from radiationless decay at a CI in solution that is hindered in the aggregate state. We also highlight how intermolecular interactions modulate the photophysics in the aggregate phase, in terms of fluorescence quantum yield and emission color.
Synthesis and Properties of Benzo‐Fused Indeno[2,1‐c]fluorenes
Authors: Jousselin‐Oba Tanguy , Deal Parker E. , Fix Aaron G. , Frederickson Conerd K. , Vonnegut Chris L. , Yassar Abderrahim , Zakharov Lev N. , Frigoli Michel , Haley Michael M. 
Published: December 2018

AbstractA set of fully‐conjugated indenofluorenes has been synthesized and confirmed by solid‐state structure analysis. The indeno[2,1‐c]fluorenes and their benzo‐fused analogues all contain the antiaromatic as‐indacene core. The molecules possess high electron affinities and show a broad absorption that reaches into the near‐IR region of the electromagnetic spectrum. All of the featured compounds reversibly accept up to two electrons as revealed by cyclic voltammetry. Analysis of molecule tropicity using NICS‐XY scan calculations shows that, while the as‐indacene core is less paratropic than s‐indacene, benz[a]‐annulation further reduces the antiaromaticity of the core. Antiaromatic strength of the as‐indacene core can also be tuned by the position of fusion of additional arenes on the outer rings.
A PDE breach to the SDRE
Authors: Rafee Nekoo Saeed 
Published: December 2018

AbstractThe state‐dependent Riccati equation (SDRE) is a nonlinear optimal controller derived from applying optimality conditions on a Hamiltonian equation. A co‐state vector is involved in the derivation process. This has been commonly considered a function of time only, despite the existence of states in the co‐state vector. This has resulted in a series of nonlinear coupled ordinary differential equations (ODEs) with a final boundary condition, known as the SDRE. In this work, for the first time, the co‐state vector is regarded as a function of time and states that results in a partial differential equation (PDE) instead of an ODE. The new governing equation is named partial differential state‐dependent Riccati equation (PDSDRE), and the PDE provides a tensor for gain over domains of time and states. Since the generated PDE is highly nonlinear, the solution to the PDSDRE is proposed based on the method of lines (MOL), which is an extension to the finite difference method (FDM). The proposed approach is implemented on both scalar and second order systems and is compared with an SDRE technique to validate the results and show the advantages of proposed structure.
Fuzzy adaptive nonlinear sensor‐fault tolerant control for a quadrotor unmanned aerial vehicle
Authors: Hu Chaofang , Cao Lei , Zhou Xianpeng , Sun Binghan , Wang Na 
Published: December 2018

AbstractIn this paper, a novel fuzzy adaptive nonlinear fault tolerant control design scheme is proposed for attitude dynamics of quadrotor UAV subjected to four sensor faults (bias, drift, loss of accuracy, loss of effectiveness). The sensor faults in Euler angle loop are transformed equivalently into a mismatched uncertainty vector, and other unknown items involving faults, uncertain parameters and external disturbances in angular velocity loop are lumped into an unknown nonlinear function vector. Fuzzy logic systems with adaptive parameters are used to approximate the mismatched uncertainty and lumped nonlinear function vectors. Dynamic surface control is applied to design the fault tolerant controller, and sliding mode control is introduced to improve the control accuracy. All signals of the closed‐loop control system are proved to be semi‐global uniformly ultimately bounded. Simulations demonstrate the effectiveness of the proposed approach for sensor faults.
Preparation and in vitro/in vivo evaluation of anastrozole reservoir‐type intravaginal ring
Authors: Xia Liangyu , Qiu Shunchen , Liu Zhenqi , Ning Meiying 
Published: December 2018

AbstractThis report details the preparation of anastrozole (ATZ) reservoir‐type intravaginal ring (IVR) and the detection of the concentration of ATZ in beagle dog plasma by liquid chromatography–tandem mass spectrometry (LC–MS/MS). An ATZ reservoir‐type IVR which included ATZ silicone elastomer core and a nonactive silicone layer was manufactured by reaction injection moulding at 80°C for 20 min. An in vitro release experiment was performed under sink conditions and the samples were determined by high‐performance liquid chromatography. A bioanalytical method was developed and validated for determination of ATZ in beagle dog plasma for IVR development. The analytical method consisted of the extraction of plasma samples and determination of ATZ by LC–MS/MS using buspirone as the internal standard. Separation was achieved on a Kinetex‐C18 110A column (3 × 30 mm, 2.6 μm, Phenomenex) using step‐gradient mobile phase and an isocratic flow rate consisting of formic acid. Protonated ions formed by a turboion spray in the positive mode was used to detect the analyte (ATZ) and internal standard. The MS–MS detection was performed on a triple quadrupole mass spectrometer equipped with electrospray ionization source. The mass spectrometer was operated in the multiple reaction monitoring mode. The mass transition ion‐pair was followed as m/z from 294.10 to 225.08 for anastrozole and m/z from 386.23 to 122.11 for buspirone. The results proved that the correlation between in vitro and in vivo analyses was relatively good.
A Review of Methodologies for Safety and Hazard Management in Chemical Industries
Authors: Chikhalikar Atharva Shashank , Jog Sachin Hemant 
Published: December 2018

AbstractThe growth in chemical industry has also led to the use of more hazardous chemicals, most often at extreme pressures and temperatures. This escalates the risk factors of a particular operation. Due to this, safety, risk assessment, and hazard management have gained utmost importance. Though a complete, full‐proof mechanism is not achievable, efforts are made to minimize the hazard level with a comprehensive and exhaustive survey of the available methods and develop a superior safety mechanism. Various measures like risk assessment, hazard analysis, thermal safety analysis, and safety indices are in place and to be incorporated at the design stage to have inherently safer processes. The present paper reviews these safety indices, surveys several modern methods and techniques used in the modern chemical industries for ensuring safety, preventing hazards, and for risk assessment. Various methodologies and techniques are compared, categorized into qualitative, quantitative, and hybrid techniques. The current and future trends of developments in this field have also been reviewed. As a rigorous breakdown analysis of a disaster can help in designing new reliable safety measures, an exemplary case study is presented.
Electrochemistry at Deep‐Sea Hydrothermal Vents: Utilization of the Thermodynamic Driving Force towards the Autotrophic Origin of Life
Authors: Ooka Hideshi , McGlynn Shawn E. , Nakamura Ryuhei 
Published: December 2018

AbstractTemperature gradients are an under‐utilized source of energy with which to drive chemical reactions. Here, we review our past efforts to understand how deep‐sea hydrothermal vents may harness thermal energy to promote difficult chemical reactions such as CO2 reduction. Strategies to amplify the driving force using temperature will be covered first, followed by a discussion on how spatially separated thermodynamic gradients can be used to regulate reaction selectivity. Although desirable material properties of hydrothermal vent walls have been inferred previously from the bioenergetic membranes of modern cells, strategies based on fundamental laws of physical chemistry allow naturally occurring chimney minerals to circumvent the lack of structural and catalytic optimization. The principles that underlie both the establishment and the utilization of the thermodynamic driving force at hydrothermal vents can be employed in abiotic systems such as the modern chemical industry, yielding insight into carbon fixation reactions important today and possibly at the autotrophic origin of life.
A High‐Performance Dual‐Ion Battery Enabled by Conversion‐Type Manganese Silicate Anodes with Enhanced Ion Accessibility
Authors: Hao Shu‐Meng , Qu Jin , Chang Wei , Zhang Yu‐Jiao , Tang Yongbing , Yu Zhong‐Zhen 
Published: December 2018

AbstractLimited by the sluggish kinetics of conversion‐type anodes from huge diffusion‐controlled phase transformation and unsatisfactory capacities of intercalation/alloy‐type anodes, the performances of lithium‐based dual ion batteries (LDIBs) remain to be promoted. Herein, for the first time, ultra‐small manganese silicate (MS) nanosheets anchored on reduced graphene oxides (MSR) with enhanced diffusion kinetics are constructed, realizing the construction of high performance LDIBs on the basis of conversion‐type anodes. The ion diffusion rate of MSR is promoted by in situ coating Li4SiO4 ionic conductor on the electrode surface during lithiation process. Simultaneously, the ion diffusion pathways are shortened by partially converting the diffusion‐controlled bulk reaction to surface reaction with massive pseudocapacitive contribution. Consequently, the MSR‐based LDIB exhibits superior electrochemical performances with discharge capacities of 191 mA h g−1 at 0.5 C and 128 mA h g−1 at 2 C after 150 cycles, exceeding to those of reported LDIBs and benefiting the future electrode design of LDIBs.
Untersuchung der batchweisen Azeotroprektifikation zur Trennung des Gemischs Essigsäure/Wasser
Authors: Millenautzki Thomas , Cieplik Ronny , Barbe Stéphan 
Published: December 2018

AbstractHauptaugenmerk dieser Arbeit wurde auf die Tauglichkeit der UNIFAC‐Methode in Bezug auf die batchweise Azeotroprektifikation eines Essigsäure/Wasser/Ethylacetat‐Gemischs gelegt. Experimentelle Daten einer batchweisen Azeotroprektifikation mit vorgeschalteter Gegenstrom‐Flüssig/Flüssig‐Extraktion im Pilotmaßstab wurden generiert. Eine schnellfunktionierende Analytik wurde entwickelt und vorgestellt und die gewonnenen Daten wurden für die Validierung der numerischen Simulation verwendet. Der allgemeine Verlauf der Rektifikation, insb. die Kopftemperatur und Destillatzusammensetzung, wurde von dem Modell bestätigt.