bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐Temperature Photochromism of Fe‐Doped SrTiO3 Caused by UV‐Induced Bulk Stoichiometry Changes
Authors: Viernstein Alexander , Kubicek Markus , Morgenbesser Maximilian , Walch Gregor , Brunauer Georg Christoph , Fleig Jürgen
Published: April 2019

The impact of UV irradiation on Fe‐doped SrTiO3 (Fe:STO) single crystals is investigated at elevated temperatures. Illumination leads to incorporation of oxygen into the single crystals and thus to a decreasing oxygen vacancy concentration and oxidation of Fe3+ to Fe4+. The Fe4+ ions cause a color change from transparent/brownish to black. This photochromic blackening due to stoichiometry changes at elevated temperatures is irreversible at room temperature, but annealing at high temperatures, for example at 700 °C, can restore the original stoichiometry and color. Absorbance changes due to UV irradiation are monitored by ex situ and in situ UV–vis spectroscopy experiments and changes in electrical properties are measured by van der Pauw measurements and in‐plane electrochemical impedance spectroscopy. After 1140 min of illumination at 440 °C, for example, electrical measurements reveal a conductivity increase by more than a factor of 5 due to the enhanced hole concentration in blackened Fe:STO. In addition, UV illumination increases the oxygen chemical potential up to a calculated p(O2) of more than 109 Pa in Fe:STO. Hence, UV light can be used to tune the color, but also electrical properties of Fe:STO by directly impacting the bulk defect concentrations.
Band Gap Engineering Improves the Efficiency of Double Quantum Dot Upconversion Nanocrystals
Authors: Yang Gaoling , Meir Noga , Raanan Dekel , Oron Dan
Published: April 2019

Solution‐processed core/multishell semiconductor quantum dots (QDs) could be tailored to facilitate the carrier separation, promotion, and recombination mechanisms necessary to implement photon upconversion. In contrast to other upconversion schemes, upconverting QDs combine the stability of an inorganic crystalline structure with the spectral tunability afforded by quantum confinement. Nevertheless, their upconversion quantum yield (UCQY) is fairly low. Here, design rules are uncovered that enable to significantly enhance the performance of double QD upconversion systems, and these findings are leveraged to fabricate upconverting QDs with increased photon upconversion efficiency and reduced saturation intensities under pulsed excitation. The role of the intra‐QD band alignment is exemplified by comparing the upconversion process in PbS/CdS/ZnSe QDs with that of PbS/CdS/CdSe ones with variable CdSe shell thicknesses. It is shown that electron delocalization into the shell leads to a longer‐lived intermediate state in the QDs, facilitating further absorption of photons, and enhancing the upconversion process. The performance of these upconversion QDs under pulsed excitation versus continuous pumping is also compared; the reasons for the significant differences between these two regimes are discussed. The results show how one can overcome some of the limitations of previous upconverting QDs, with potential applications in biophotonics and infrared detection.
Beetle‐Inspired Assembly of Heterostructured Lamellar Membranes with Polymer Cluster–Patterned Surface for Enhanced Molecular Permeation
Authors: Wang Jingtao , Yuan Zhijie , Wu Xiaoli , Li Yifan , Chen Jingjing , Jiang Zhongyi
Published: April 2019

2D lamellar membranes hold great promise in efficient molecular separations of liquid and gas mixtures. However, the simultaneous realization of high permeation and precise sieving (i.e., overcoming the permeation–rejection tradeoff) of membranes poses a great challenge. Inspired by the structures and functions of the beetle's back, the heterostructured lamellar membranes fabricated through facile and controllable electrostatic atomization method are reported. Particularly, hydrophobic polymer clusters are patterned on hydrophilic laminate (graphene oxide) surfaces to realize the hydrophilic/hydrophobic heterostructure. It shows that the fast dissolution for nonpolar solvents is achieved by the strong affinity polymer clusters, and the ultralow‐barrier diffusion is achieved by the weak affinity laminate channels. Therefore, the permeance is remarkably enhanced (over 7 times for nonpolar solvents), while fully retaining membrane rejection. In contrast, hydrophilic clusters are patterned on hydrophobic laminate (reduced graphene oxide) surfaces and exhibit similar behaviors toward polar solvents. Furthermore, the lamellar membrane displays highly ordered layer‐by‐layer stacking, affording precise molecular rejection. Besides, the lamellar membrane acquires lower thermodynamic energy and hence superior stability under ultrasonic and strong acid or alkali environments, manifesting great potential for long‐term practical operation.
Intercalated Electrolyte with High Transference Number for Dendrite‐Free Solid‐State Lithium Batteries
Authors: Chen Long , Li Wenxin , Fan Li‐Zhen , Nan Ce‐Wen , Zhang Qiang
Published: April 2019

Solid‐state lithium (Li) batteries using solid electrolytes and Li anodes are highly desirable because of their high energy densities and intrinsic safety. However, low ambient‐temperature conductivity and poor interface compatibility of solid electrolytes as well as Li dendrite formation cause large polarization and poor cycling stability. Herein, a high transference number intercalated composite solid electrolyte (CSE) is prepared by the combination of a solution‐casting and hot‐pressing method using layered lithium montmorillonite, poly(ethylene carbonate), lithium bis(fluorosulfonyl)imide, high‐voltage fluoroethylene carbonate additive, and poly(tetrafluoroethylene) binder. The electrolyte presents high ionic conductivity (3.5 × 10−4 S cm−1), a wide electrochemical window (4.6 V vs Li+/Li), and high ionic transference number (0.83) at 25 °C. In addition, a 3D Li anode is also fabricated via a facile thermal infusion strategy. The synergistic effect of high transference number intercalated electrolyte and 3D Li anode is more favorable to suppress Li dendrites in a working battery. The solid‐state batteries based on LiFePO4 (Al2O3 @ LiNi0.5Co0.2Mn0.3O2), CSE, and 3D Li deliver admirable cycling stability with discharge capacity 145.9 mAh g−1 (150.7 mAh g−1) and capacity retention 91.9% after 200 cycles at 0.5 C (92.0% after 100 cycles at 0.2 C) at 25 °C. This work affords a splendid strategy for high‐performance solid‐state battery.
One‐Step Fabrication of Ultralow Pt Loading High Efficiency Proton Exchange Membrane for Water Electrolysis by Conventional E‐Beam Metal Deposition
Authors: Wang Yanyan , Yu Xue , Liu Gen , Zhu Xiaodong , Xu Rui , Ji Mei , Ma Yanqing , Ma Lei
Published: April 2019

Proton exchange membrane water electrolysis (PEMWE) is known as an effective and environmental‐friendly method for hydrogen production. However, the process is hindered by the necessity of large loading of high‐priced noble metals in the conventional approaches. To resolve this problem, a highly efficient Nafion‐based catalyst and proton exchange system are developed, which only need ultralow platinum loading by direct e‐beam evaporation deposition. Scanning electron microscopy is performed before and after the deposition, which reveals a very smooth morphology. By assembling the PEMWE device with above‐mentioned cathode and conventional iridium black anode, the current density reaches 500 mA cm−2 with a platinum loading of only 0.00379 mg cm−2 at 1.64 V under 80 °C. A mass activity of ≈132 A mg−1 is achieved, which is one order of magnitude higher than previously reported results. Moreover, powered by a commercial silicon solar cell, it realizes a solar‐to‐hydrogen conversion efficiency up to 8.26%. This work opens up an avenue of fabricating PEMWE with an ultralow catalyst loading, which may have enormous potential for future industrial scale applications.
Effect of Constituent Materials on Composite Performance: Exploring Design Strategies via Machine Learning
Authors: Chen Chun‐Teh , Gu Grace X.
Published: April 2019

Nature assembles a range of biological composites with remarkable mechanical properties despite being composed of relatively weak polymeric and ceramic components. However, the architectures of biomaterials cannot be considered as optimal designs for engineering applications since biomaterials are constantly evolving for multiple functions beyond carrying external loading. Here, it is aimed to develop an intelligent approach to design superior composites from scratch—starting from constituent materials. A systematic computational investigation of the effect of constituent materials (assumed to be perfectly brittle) on the behavior of composites using an integrated approach combining finite element method, molecular dynamics, and machine learning (ML) is reported. It is demonstrated that instead of using brute‐force methods, machine learning is a much more efficient approach and can generate optimal designs with similar performance to those obtained from an exhaustive search. Furthermore, it is shown that the toughening and strengthening mechanism observed in composites at the continuum‐scale by combining stiff and soft constituents is valid for nanomaterials as well. Results show that high‐performing designs of graphene nanocomposites can be generated using our ML approach. This novel ML‐based design framework can be applied to other material systems to study a variety of structure–property relationships over several length‐scales.
Synergy of Nb Doping and Surface Alloy Enhanced on Water–Alkali Electrocatalytic Hydrogen Generation Performance in Ti‐Based MXene
Authors: Du Cheng‐Feng , Sun Xiaoli , Yu Hong , Liang Qinghua , Dinh Khang Ngoc , Zheng Yun , Luo Yubo , Wang Zhiguo , Yan Qingyu
Published: April 2019

Presented are the theoretical calculation and experimental studies of a Ti3C2Tx MXene‐based nanohybrid with simultaneous Nb doping and surface transition metal alloy modification. Guided by the density functional theory calculation, the Nb doping can move up the Fermi energy level to the conduction band, thus enhancing the electronic conductivity. Meanwhile, the surface modification by Ni/Co alloy can moderate the surface M–H affinity, which will further enhance the hydrogen evolution reaction (HER) activity. A series of Ni/Co alloy attached on Nb‐doped Ti3C2Tx MXene nanohybrids (denoted as NiCo@NTM) are successfully prepared. As expected, the Ni0.9Co0.1@ NTM nanohybrids present an extraordinary HER activity in alkaline solution, which only needs an overpotential (η) of 43.4 mV to reach the current density of 10 mA cm−2 in 1 m KOH solution and shows good stability. The performance of the Ni0.9Co0.1@ NTM nanohybrids is comparable to the commercial 10% Pt/C electrode (34.4 mV@10 mA cm−2) and is better than most state‐of‐the‐art Pt‐free HER catalysts. Inspired by the facile synthesis process and chemical versatility of both MXene and transition metal alloys, the nanohybrids reported here are promising non‐noble metal electrocatalysts for water–alkali electrolysis.
Quantitative Third Harmonic Generation Microscopy for Assessment of Glioma in Human Brain Tissue
Authors: Zhang Zhiqing , de Munck Jan C. , Verburg Niels , Rozemuller Annemieke J. , Vreuls Willem , Cakmak Pinar , van Huizen Laura M. G. , Idema Sander , Aronica Eleonora , de Witt Hamer Philip C. , Wesseling Pieter , Groot Marie Louise
Published: April 2019

Distinguishing tumors from normal brain cells is important but challenging in glioma surgery due to the lack of clear interfaces between the two. The ability of label‐free third harmonic generation (THG) microscopy in combination with automated image analysis to quantitatively detect glioma infiltration in fresh, unprocessed tissue in real time is assessed. The THG images reveal increased cellularity in grades II–IV glioma samples from 23 patients, as confirmed by subsequent hematoxylin and eosin histology. An automated image quantification workflow is presented for quantitative assessment of the imaged cellularity as a reflection of the degree of glioma invasion. The cellularity is validated in three ways: 1) Quantitative comparison of THG imaging with fluorescence microscopy of nucleus‐stained samples demonstrates that THG reflects the true tissue cellularity. 2) Thresholding of THG cellularity differentiates normal brain from glioma infiltration, with 96.6% sensitivity and 95.5% specificity, in nearly perfect (93%) agreement with pathologists. 3) In one patient, a good correlation between THG cellularity and preoperative magnetic resonance and positron emission tomography imaging is demonstrated. In conclusion, quantitative real‐time THG microscopy accurately assesses glioma infiltration in ex vivo human brain samples, and therefore holds strong potential for improving the accuracy of surgical resection.
Phase‐Transited Lysozyme‐Driven Formation of Self‐Supported Co3O4@C Nanomeshes for Overall Water Splitting
Authors: Ha Yuan , Shi Lingxia , Chen Ziliang , Wu Renbing
Published: April 2019

The development of highly efficient catalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is of paramount importance in water splitting. Herein, a phase‐transited lysozyme (PTL) is employed as the platform to synthesize nitrogen‐doped Co3O4@C nanomesh with rich oxygen vacancies supported on the nickel foam (N‐Co3O4@C@NF). This PTL‐driven N‐Co3O4@C@NF integrates the advantages of porous structure, high exposure of surface atoms, strong synergetic effect between the components and unique 3D electrode configuration, imparting exceptional activity in catalyzing both HER and OER. Remarkably, an alkaline electrolyzer assembled by N‐Co3O4@C@NF as both cathode and anode delivers a current density of 10 mA cm−2 at an ultralow cell voltage of 1.40 V, which is not only much lower than that of the commercially noble Pt/C and IrO2/C catalyst couple (≈1.61 V) but also a new record for the overall water splitting. The finding may open new possibilities for the design of bifunctional electrocatalysts for application in practical water electrolysis.
Energy Transfer between Tb3+ and Eu3+ in LaPO4: Pulsed versus Switched‐off Continuous Wave Excitation
Authors: Luo Yuxia , Liu Zhenyu , Wong Hon Tung , Zhou Lei , Wong Ka‐Leung , Shiu Kwok Keung , Tanner Peter A.
Published: April 2019

The energy transfer (ET) between Tb3+ and Eu3+ is investigated experimentally and with available theoretical models in the regime of high Tb3+ concentrations in ≈30 nm LaPO4 nanoparticles at room temperature. The ET efficiency approaches 100% even for lightly Eu3+‐doped materials. The major conclusion from the use of pulsed laser excitation and switched‐off continuous wave laser diode excitation is that the energy migration between Tb3+ ions, situated on La3+ sites with ≈4 Å separation, is not fast. The quenching of Tb3+ emission in singly doped LaPO4 only reduces the luminescence lifetime by ≈50% in heavily doped samples. Various theoretical models are applied to simulate the luminescence decays of Tb3+ and Tb3+, Eu3+‐doped LaPO4 samples of various concentrations and the transfer mechanism is identified as forced electric dipole at each ion.
Constructing Metal Arch Nanobridges Utilizing a Photothermal‐Induced Nanobonding Technique
Authors: Ghosh Pintu , Lu Jinsheng , Luo Hao , Wang Wei , Xu Ziquan , Qiu Min , Li Qiang
Published: April 2019

Construction of multilayered arch nanobridges and nanocantilever structures consisting of silver nanowires using a photothermal‐induced nanobonding technique is demonstrated. The fabricated nanobridges are of different height (300 nm to 20 µm) and span (25–70 µm). Their current–voltage characteristic curves indicate superior electrical connection between the metal nanowires and the abutments (gold thin film). Moreover, super mechanical strength of these arch nanobridges and nanocantilevers is demonstrated by putting gold nanoplates (a few tens of nm thick, a few tens of µm in diameter, and a maximum weight of 3 pN—about 20 times heavier than the silver nanowire of same length) on top of these nanostructures. The multilayered arch nanobridges demonstrate their potential applicability as short‐circuit‐free multipronged electronic connections in nanoelectronic devices. Furthermore, by recording the change in vibration frequency due to proximity of foreign contamination, these nanobridges and the nanocantilevers can be utilized to identify them; that is, these nanostructures can be used as biological sensors to detect viruses, bacteria, and other pathogens.
The Thermoelectric Properties of Bismuth Telluride
Authors: Witting Ian T. , Chasapis Thomas C. , Ricci Francesco , Peters Matthew , Heinz Nicholas A. , Hautier Geoffroy , Snyder G. Jeffrey
Published: April 2019

Bismuth telluride is the working material for most Peltier cooling devices and thermoelectric generators. This is because Bi2Te3 (or more precisely its alloys with Sb2Te3 for p‐type and Bi2Se3 for n‐type material) has the highest thermoelectric figure of merit, zT, of any material around room temperature. Since thermoelectric technology will be greatly enhanced by improving Bi2Te3 or finding a superior material, this review aims to identify and quantify the key material properties that make Bi2Te3 such a good thermoelectric. The large zT can be traced to the high band degeneracy, low effective mass, high carrier mobility, and relatively low lattice thermal conductivity, which all contribute to its remarkably high thermoelectric quality factor. Using literature data augmented with newer results, these material parameters are quantified, giving clear insight into the tailoring of the electronic band structure of Bi2Te3 by alloying, or reducing thermal conductivity by nanostructuring. For example, this analysis clearly shows that the minority carrier excitation across the small bandgap significantly limits the thermoelectric performance of Bi2Te3, even at room temperature, showing that larger bandgap alloys are needed for higher temperature operation. Such effective material parameters can also be used for benchmarking future improvements in Bi2Te3 or new replacement materials.
Ankle brachial index (ABI) in a cohort of older women in the Philippines: Prevalence of peripheral artery disease and predictors of ABI
Authors: Kuzawa Christopher W. , Barrett Tyler M. , Borja Judith B. , Lee Nanette R. , Aquino Celine T. , Adair Linda S. , McDade Thomas W.
Published: April 2019

Objective

Cardiovascular disease (CVD) is rising in low and middle‐income countries, but studies of CVD epidemiology in such settings often focus on risk factors rather than measures of disease progression. Here we use the ankle brachial index (ABI) to assess the prevalence of peripheral artery disease (PAD) among older women living in Metropolitan Cebu, Philippines, and relationships between ABI and CVD risk factors and body composition.

Methods

ABI was measured using the Doppler technique in 538 female participants in the 2015 Cebu Longitudinal Health and Nutrition Survey (mean age 58 years, range 47‐78 years). ABI was related to a panel of CVD risk factors measured in 2005 and 2012, and to 2012 body composition measures.

Results

The prevalence of PAD (1.8%) was among the lowest reported in any comparably‐aged sample, and only 9.9% of participants had an ABI indicating borderline PAD risk. Smoking (P < 0.011) and use of CVD medications (P < 0.0001) predicted lower ABI (indicating higher PAD risk), which was also lower in relation to 2012 systolic blood pressure (P < 0.054). ABI was unrelated to other CVD risk factors. An apparent protective relationship between body mass index (BMI) and ABI, noted in previous studies, was found to be confounded by protective relationships between ABI and fat free mass, height, and grip strength (all P < 0.05).

Conclusions

The prevalence of PAD is low in Cebu Longitudinal Health and Nutrition Survey participants, and ABI was related to few CVD risk factors. Past reports of lower PAD risk in relation to BMI may reflect confounding by lean mass, which has protective relationships with ABI.
The role of glutamate receptors in attention‐deficit/hyperactivity disorder: From physiology to disease
Authors: Huang Xin , Wang Min , Zhang Qi , Chen Xinzhen , Wu Jing
Published: April 2019

Attention‐deficit hyperactivity disorder (ADHD) is the most common psychiatric disorder in children and adolescents, which is characterized by behavioral problems such as attention deficit, hyperactivity, and impulsivity. As the receptors of the major excitatory neurotransmitter in the mammalian central nervous system (CNS), glutamate receptors (GluRs) are strongly linked to normal brain functioning and pathological processes. Extensive investigations have been made about the structure, function, and regulation of GluR family, describing evidences that support the disruption of these mechanisms in mental disorders, including ADHD. In this review, we briefly described the family and function of GluRs in the CNS, and discussed what is recently known about the role of GluRs in ADHD, that including GluR genes, animal models, and the treatment, which would help us further elucidate the etiology of ADHD.
Pd‐Catalyzed Decarboxylative Allylation for Stereoselective Syntheses of Allylic Alcohols bearing a Quaternary Carbon Center
Authors: Shi Linlin , He Yingdong , Gong Jianxian , Yang Zhen
Published: April 2019

Olefins play a vital role in the fields of bioscience, medicine, and chemistry. Stereo‐defined olefins are important resource in both chemical laboratory and industry. Using a palladium‐catalyzed decarboxylative transformation of vinyl cyclic carbonates, we have developed an efficient and reliable method for the direct construction of highly substituted olefins with the concomitant formation of a new Csp3‐Csp3 bond. The desired olefins could be generated in reasonable yields with good stereoselectivities, in contrast to the existing methods, which are usually non‐stereoselective. The palladium‐catalyzed decarboxylative transformation will undoubtedly provide new synthetic routes for the formation of multi‐substituted allylic scaffolds.
Diaphysator: An online application for the exhaustive cartography and user‐friendly statistical analysis of long bone diaphyses
Authors: Santos Frédéric , Lacoste Jeanson Alizé
Published: April 2019

The cross‐sectional geometry (CSG) of long bone diaphyses is used in bioanthropology to evaluate their resistance to biomechanical constraints and to infer life‐history‐related patterns such as mobility, activity specialization or intensity, sexual dimorphism, body mass and proportions. First limited by technical analytical constraints to the analysis of one or two cross sections per bone, it has evolved into the analysis of cross sections of the full length of the diaphyseal part of long bones. More recently, researchers have developed analytical tools to map the cortical thickness of entire diaphyses to evaluate locomotor signatures. However, none of these analytical tools are easy to use for scientists who are not familiar with computer programming, and some statistical procedures–such as mapping the correlation coefficients of the diaphyseal thickness with various parameters have yet to be made available. Therefore, we developed an automated and open‐source application that renders those analyses (both CSG and cortical thickness) in a semiautomated and user friendly manner. This application, called “Diaphysator”, is associated with another free software (“Extractor”, presented in Dupej et al. (2017). American Journal of Physical Anthropology, 164, 868–876). Diaphysator can be used as an online application (https://diaphysator.shinyapps.io/maps) or as a package for R statistical software. Along with the mean maps of cortical thickness and mean CSG parameter graphs, the users can evaluate the correlations and partial correlations of both CSG parameters at every cross section along the diaphyseal length, and cortical thickness data points of the entire diaphysis, with any factor such as age, sex, stature, and body mass.
Esophageal IgE, IgG4, and mucosal eosinophilia in individuals with dysphagia
Authors: Ramaswamy Apoorva T. , No Jae Seong , Anderson Lillye , Solomon Aliza , Ciecierega Thomas , Barfield Elaine , Chien Kimberly , Schnoll‐Sussman Felice , Reisacher William R.
Published: April 2019

Background

Eosinophilic esophagitis (EoE) is an inflammatory disease of the esophagus, producing failure to thrive in infants and dysphagia with food impaction in older children and adults. Although most people with EoE manifest atopic/allergic disease, the specific allergens to which immunoglobulin E (IgE) is directed, if any, have not yet been characterized.

Methods

Mucosal brush biopsy (MBB) and solid tissue biopsy (STB) specimens were prospectively obtained from 25 individuals with dysphagia and suspicion of EoE. Specific IgE (sIgE) against 112 epitopes from airborne and food proteins, antigens known to cause a polyclonal IgE response and IgG4 to food allergens, were measured.

Results

There was no difference in total IgE harvested between the 2 biopsy methods (p > 0.05) or between the EoE‐positive (N = 12) and EoE‐negative (N = 13) groups (p > 0.05). None of the samples in either group contained measurable serum IgE to any of the airborne or food proteins tested, but low levels of IgE specific to Candida and Staphylococcus enterotoxins were detected. Low levels of IgG4 specific to wheat, soy, peanut, and egg were also detected.

Conclusions

Both MBB and STB are able to harvest measureable levels of IgE and IgG4 from the esophageal mucosa. Low levels of serum‐specific IgE suggest that other inflammatory mechanisms, besides type I, IgE‐mediated, allergen‐specific hypersensitivity, may act as the primary catalyst for mucosal eosinophilia. Clarifying the role of both IgE‐mediated and non‒IgE‐mediated inflammatory mechanisms will help identify more targeted diagnostic and treatment strategies for individuals who present with dysphagia and esophageal eosinophilia.
Photoenzymatic Catalysis Enables Radical‐Mediated Ketone Reduction in Ene‐Reductases
Authors: Sandoval Braddock A. , Kurtoic Sarah I. , Chung Megan M. , Biegasiewicz Kyle F. , Hyster Todd K.
Published: April 2019

Flavin‐dependent ene‐reductases (EREDs) are known to stereoselectively reduce activated alkenes, but are inactive toward carbonyls. Demonstrated here is that in the presence of photoredox catalysts, these enzymes will reduce aromatic ketones. Mechanistic experiments suggest this reaction proceeds through ketyl radical formation, a reaction pathway that is distinct from the native hydride‐transfer mechanism. Furthermore, this reactivity is accessible without modification of either the enzyme or cofactors, allowing both native and non‐natural mechanisms to occur simultaneously. Based on control experiments, we hypothesize that binding to the enzyme active site attenuates the reduction potential of the substrate, enabling single‐electron reduction. This reactivity highlights opportunities to access new catalytic manifolds by merging photoredox catalysis with biocatalysis.
Electrochromic Poly(chalcogenoviologen)s as Anode Materials for High‐Performance Organic Radical Lithium‐Ion Batteries
Authors: Li Guoping , Zhang Bingjie , Wang Jianwei , Zhao Hongyang , Ma Wenqiang , Xu Letian , Zhang Weidong , Zhou Kun , Du Yaping , He Gang
Published: April 2019

A series of electrochromic electron‐accepting poly(chalcogenoviologen)s with multiple, stable, and reversible redox centers were used as anodic materials in organic radical lithium‐ion batteries (ORLIBs). The introduction of heavy atoms (S, Se, and Te) into the viologen scaffold significantly improved the capacity and cycling stability of the ORLIBs. Notably, the poly(Te‐BnV) anode was able to intercalate 20 Li ions and showed higher conductivity and insolubility in the electrolyte, thus contributing to a reversible capacity of 502 mAh g−1 at 100 mA g−1 when the Coulombic efficiency approached 100 %. The charged/discharged state of flexible electrochromic batteries fabricated from these anodic materials could be monitored visually owing to the unique electrochromic and redox properties of the materials. This study opens a promising avenue for the development of organic polymer‐based electrodes for flexible hybrid visual electronics.
Use of High‐Intensity Ultrasound to Change the Physical Properties of Oleogels and Emulsion Gels
Authors: da Silva Thais Lomonaco Teodoro , Arellano Daniel Barrera , Martini Silvana
Published: April 2019

The objective of this work was to evaluate the effect of high‐intensity ultrasound (HIU) on the physical properties of a soft oleogel (2% of candelilla wax, 2% of monoacylglycerol, and 2% of hardfat) and of water‐in‐oil (W/O) emulsion gels (EG) with various amounts of water (0%, 5%, and 25%). Physical properties of these systems such as thermoresistance, microstructure, melting profile, hardness, rheology, and oil loss were measured. When HIU was applied to the oleogel for 3 min using a 3.2 mm‐diameter tip at an amplitude of vibration of 216 μm, a reduction in crystal size and crystal area (P < 0.05) was observed with an increase in hardness and no change in G′ nor in oil loss compared to the nonsonicated oleogel. Other sonication conditions (lower power levels, shorter durations, and bigger tips) tested in this study reduced the hardness and elasticity of the sample and increased oil loss. When HIU (3.2 mm‐diameter tip, 216 μm, 3 min) was used in emulsions, harder and more elastic (P < 0.05) samples were obtained only in the samples with 25% water. This study shows that the texture of oleogels and EG with 25% of water can be improved by using HIU. The impact of these results is that the fat content of an EG can be reduced by 25% by adding water and HIU can be used to recover the structure lost due to water addition.
Improving tribological properties of phenolic resin/carbon fiber composites using m‐Si3N4@PANI core–shell particles
Authors: Fan Chunlei , Li Honglong , Jin Lin , Zhang Mengjie , Xiao Linghan , Li Ming , Ao Yuhui
Published: April 2019

Phenolic resin/carbon fiber (PF/CF) composites have good tribological properties; however, their extensive applications are limited because of the poor thermal conductivity of the phenolic resins. In this work, core‑shell particles of polyaniline‐coated (3‐aminopropyl) triethoxysilane‐modified β‐Si3N4 (m‐SiN@PANI) were used to enhance the tribological, electrical, and thermal conductivity properties of a PF/CF composite. A core‑shell particle, consisting of m‐SiN@PANI, was characterized by Fourier Transform Infrared Spectrometry, X‐Ray Diffraction, Scanning Electron Microscope, and Transmission Electron Microscope. The friction, thermal, and electrical properties of the composites were characterized by multifunctional vertical friction testing, wear measurement testing, thermogravimetric analysis, thermal constant analysis, and electrical conductivity testing. Remarkably, the test results showed that compared with the wear surface of the PF/CF composite, that of the phenolic resin/(2.0 wt % m‐SiN@PANI)/carbon fiber composite exhibited a smoother morphology. The results indicated that the addition of m‐SiN@PANI effectively improved the thermal conductivity, electrical conductivity, friction coefficient, and wear rate of the composites, which were 3.164 Wm−1 K−1, 5.33 × 10−6 S/m, 0.1681 and 1.13 × 10−8 mm3/Nm, respectively. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47785.
Endocytosis and Transport of Growth Factor Receptors in Peripheral Axon Regeneration: Novel Lessons from Neurons Expressing Lysine‐Deficient FGF Receptor Type 1 in vitro
Authors: Hausott Barbara , Förste Alexandra , Zach Fabian , Mangger Stefan , Haugsten Ellen Margrethe , Klimaschewski Lars
Published: April 2019

In the course of peripheral nerve regeneration, axons encounter different extracellular growth factors secreted by non‐neuronal cells at the injury site and retrogradely transported after binding to neuronal membrane receptor tyrosine kinases. The present study reviews the role of receptor transport in peripheral axon outgrowth and provides novel data on trafficking of fibroblast growth factor receptor type 1 (FGFR1). Differences in receptor transport are determined by different numbers of lysine residues acting as ubiquitination sites in the intracellular receptor domain. We previously demonstrated that overexpression of mutant FGFR1‐25R (25 out of 29 intracellular lysines replaced with arginine) results in enhanced receptor recycling as compared to wild‐type FGFR1 followed by strong stimulation of elongative axon growth in vitro. Here, the effects of lysine‐deficient FGFR1 (FGFR1‐29R lacking all 29 cytoplasmic lysine residues) or of only 15 lysine mutations (FGFR1‐15R) on axon outgrowth and concomitant changes in signal pathway activation were investigated by immunocytochemistry and morphometry of cultured primary neurons. Overexpression of FGFR1‐15R in adult sensory neurons resulted in enhanced receptor recycling, which was accompanied by increased axon elongation without stimulating axon branching. By contrast, FGFR1‐29R was neither endocytosed nor axon outgrowth affected. Although overexpression of FGFR1‐15R or FGFR1‐25Ra strongly promoted elongation, we did not detect increased signal pathway activation (ERK, AKT, PLC, or STAT3) in neurons expressing mutant FGFR1 as compared with wild‐type neurons raising the possibility that other signaling pathways or signaling independent mechanisms may be involved in the axon outgrowth effects of recycled FGF receptors. Anat Rec, 302:1268–1275, 2019. © 2019 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.
Progesterone Effects in the Nervous System
Authors: Theis Verena , Theiss Carsten
Published: April 2019

The sex hormone progesterone is mainly known as a key factor in establishing and maintaining pregnancy. In addition, progesterone has been shown to induce morphological changes in the central and peripheral nervous system by increasing dendrito‐, spino‐, and synaptogenesis in Purkinje cells (Wessel et al.: Cell Mol Life Sci (2014a) 1723–1740) and increasing axonal outgrowth in dorsal root ganglia (Olbrich et al.: Endocrinology (2013) 3784–3795). These effects mediated mainly by the classical progesterone receptors (PRs) A and B seem to be limited to young neurons. It may be assumed that microRNAs (miRNAs), which are potent regulators of nervous system maturation and degeneration, are also involved in the regulation of progesterone‐mediated neuronal plasticity by altering the expression patterns of the corresponding PR A/B receptors (Theis and Theiss: Neural Regen Res (2015) 547–549, Pieczora et al.: Cerebellum (2017) 376–387). This review critically discusses current data on the neuroprotective effect of progesterone and its corresponding receptors in the nervous system, with possible regulatory processes by miRNAs. Preclinical studies on stroke and traumatic brain injury revealed neuroprotective and neuroregenerative effects of progesterone in the treatment of severe neurological diseases in animal models, but have so far failed in humans. In this context, the identification of specific miRNAs that regulate the expression of progesterone and PR could help to exploit the neuroprotective potential of progesterone for the treatment of various neurological disorders. Anat Rec, 302:1276–1286, 2019. © 2019 Wiley Periodicals, Inc.
Effect of Pulsed and Continuous Ultrasound Therapy on the Degree of Collateral Axonal Branching at the Lesion Site, Polyinnervation of Motor End Plates, and Recovery of Motor Function after Facial Nerve Reconstruction
Authors: Ozsoy Umut , Ogut Eren , Sekerci Rahime , Hizay Arzu , Rink Svenja , Angelov Doychin N.
Published: April 2019

The aim of the present study is to test whether ultrasound therapy of muscles denervated by nerve injury would improve the quality of their reinnervation by reduction of the collateral axonal branching at the lesion site and poly‐innervation degree at the neuromuscular junctions. After transection and suture of the buccal branch of the facial nerve, pulsed or continuous type of ultrasound therapy was applied to the paralyzed whisker pad muscles of rats in the course of 2 months. Instead of reduction, we found a significant increase in the collateral axonal branching after continuous ultrasound therapy when compared to the branching determined after pulsed or sham ultrasound therapy. Both types of ultrasound therapy also failed to reduce the proportion of polyinnervated end plates in the reinnervated facial muscles. Accordingly, continuous ultrasound therapy failed to restore any parameter of the motor performance of the vibrissal hairs. Application of pulsed ultrasound therapy promoted slight improvements of the functional parameters angular velocity and acceleration. The inhomogeneous structural and functional results achieved after both types of ultrasound therapy let us conclude that further studies are required to evaluate its effects on peripheral nerve regeneration. Anat Rec, 302:1314–1324, 2019. © 2019 Wiley Periodicals, Inc.
Experimental Studies on Facial Nerve Regeneration
Authors: Rink Svenja , Bendella Habib , Akkin Salih Murat , Manthou Marilena , Grosheva Maria , Angelov Doychin N.
Published: April 2019

Insufficient recovery after injury of a peripheral motor nerve is due to (1) inappropriate pathfinding as a result of axonal regrowth to inappropriate targets, (2) excessive collateral axonal branching at the lesion site, and (3) polyinnervation of the neuromuscular junctions (NMJs). The rat facial nerve model is often used because of its simple and reliable readout to measure recovery of function (vibrissal whisking). Over the last decades scientists have concentrated their efforts to combat mostly NMJ polyinnervation, because it turned out to be very difficult to reduce collateral axonal branching and impossible to navigate thousands of axons toward the original fascicles. In the past, several groups of scientists concentrated their efforts to reduce the activity‐dependent polyinnervation of NMJs by electrical stimulation of the muscles (square 0.1 msec pulses at 5 Hz). The results showed no recovery of functions and a severe reduction in the number of innervated NMJs to approximately one fifth of those observed in intact animals. More recent experiments, however, have shown that motor recovery improved significantly following mechanical stimulation of the denervated facial muscles (vibrissal and orbicularis oculi) and that restored functions could invariably be linked to reduced polyinnervation at the NMJ while the number of innervated NMJ remained the same. These results suggest that clinically feasible and effective therapies could be developed and tested in the near future. Anat Rec, 302:1287–1303, 2019. © 2019 Wiley Periodicals, Inc.
Enteric Neurogenesis During Life Span Under Physiological and Pathophysiological Conditions
Authors: Grundmann David , Loris Eva , Maas‐Omlor Silke , Schäfer Karl‐Herbert
Published: April 2019

The enteric nervous system (ENS) controls gastrointestinal key functions and is mainly characterized by two ganglionated plexus located in the gut wall: the myenteric plexus and the submucous plexus. The ENS harbors a high number and diversity of enteric neurons and glial cells, which generate neuronal circuitry to regulate intestinal physiology. In the past few years, the pivotal role of enteric neurons in the underlying mechanism of several intestinal diseases was revealed. Intestinal diseases are associated with neuronal death that could in turn compromise intestinal functionality. Enteric neurogenesis and regeneration is therefore a crucial aspect within the ENS and could be revealed not only during embryogenesis and early postnatal periods, but also in the adulthood. Enteric glia and/or enteric neural precursor/progenitor cells differentiate into enteric neurons, both under homeostatic and pathologic conditions beyond the perinatal period. The unique role of the intestinal microbiota and serotonin signaling in postnatal and adult neurogenesis has been shown by several studies in health and disease. In this review article, we will mainly focus on different recent studies, which advanced the concept of postnatal and adult ENS neurogenesis. Moreover, we will discuss the key factors and underlying mechanisms, which promote enteric neurogenesis. Finally, we will shortly describe neurogenesis of transplanted enteric neural progenitor cells. Anat Rec, 302:1345–1353, 2019. © 2019 Wiley Periodicals, Inc.
Promotion of Peripheral Nerve Regeneration by Stimulation of the Extracellular Signal‐Regulated Kinase (ERK) Pathway
Authors: Hausott Barbara , Klimaschewski Lars
Published: April 2019

Peripherally projecting neurons undergo significant morphological changes during development and regeneration. This neuroplasticity is controlled by growth factors, which bind specific membrane bound kinase receptors that in turn activate two major intracellular signal transduction cascades. Besides the PI3 kinase/AKT pathway, activated extracellular signal‐regulated kinase (ERK) plays a key role in regulating the mode and speed of peripheral axon outgrowth in the adult stage. Cell culture studies and animal models revealed that ERK signaling is mainly involved in elongative axon growth in vitro and long‐distance nerve regeneration in vivo. Here, we review ERK dependent morphological plasticity in adult peripheral neurons and evaluate the therapeutic potential of interfering with regulators of ERK signaling to promote nerve regeneration. Anat Rec, 302:1261–1267, 2019. © 2019 Wiley Periodicals, Inc.
Brief Electrical Stimulation Improves Functional Recovery After Femoral But Not After Facial Nerve Injury in Rats
Authors: Raslan Ashraf , Salem Mohamed A. M. , Al‐Hussaini Ahmed , Guntinas‐Lichius Orlando , Irintchev Andrey
Published: April 2019

Brief low‐frequency electrical stimulation (ES, 1 h, 20 Hz) of the proximal nerve stump has emerged as a potential adjunct treatment for nerve injury. Despite available experimental and clinical data, the potentials and limitations of the ES therapy still have to be defined using different animal models, types of nerves, and clinical settings. Here, we show that brief ES of the proximal stump of the transected rat femoral nerve causes, as estimated by motion analysis, enhanced functional recovery reaching preoperative levels within 5 months of injury, in contrast to the incomplete restoration in sham‐stimulated (SS) animals. The functional advantage seen in ES rats was associated with higher numbers, as compared with SS, of correctly targeted quadriceps motoneurons. In contrast, ES prior to facial nerve suture did not lead to improvement of whisking compared with SS. Lack of functional effects of the treatment was correlated with lack of changes, as compared with SS, in the precision of muscle reinnervation and frequency of abnormally innervated muscle fibers. These results show that ES is an effective therapy in a spinal nerve injury model leading to complete restoration of function. Although this finding and the safety of the procedure are encouraging, the results for the facial nerve model suggest that brief ES may not be a universal treatment for nerve injuries. Anat Rec, 302:1304–1313, 2019. © 2019 Wiley Periodicals, Inc.
Enteric Glia: S100, GFAP, and Beyond
Authors: Grundmann David , Loris Eva , Maas‐Omlor Silke , Huang Wenhui , Scheller Anja , Kirchhoff Frank , Schäfer Karl‐Herbert
Published: April 2019

Since several years, the enteric nervous system (ENS) is getting more and more in the focus of gastrointestinal research. While the main interest was credited for years to the enteric neurons and their functional properties, less attention has been paid on the enteric glial cells (EGCs). Although the similarity of EGCs to central nervous system (CNS) astrocytes has been demonstrated a long time ago, EGCs were investigated in more detail only recently. Similar to the CNS, there is not “the” EGC, but also a broad range of diversity. Based on morphology and protein expression, such as glial fibrillary acidic protein (GFAP), S100, or Proteolipid‐protein‐1 (PLP1), several distinct glial types can be differentiated. Their heterogeneity in morphology, localization, and transcription as well as interaction with surrounding cells indicate versatile functional properties of these cells for gut function in health and disease. Although NG2 is found in a subset of CNS glial cells, it did not colocalize with the glial marker S100 or GFAP in the ENS. Instead, it in part colocalize with PDGFRα, as it does in the CNS, which do stain fibroblast‐like cells in the gastrointestinal tract. Moreover, there seem to be species dependent differences. While GFAP is always found in the rodent ENS, this is completely different for the human gut. Only the compromised human ENS shows a significant amount of GFAP‐positive glial cells. So, in general we can conclude that the EGC population is species specific and as complex as CNS glia. Anat Rec, 302:1333–1344, 2019. © 2019 Wiley Periodicals, Inc.
Rheumatoid Arthritis Disease Activity Predicting Incident Clinically Apparent Rheumatoid Arthritis–Associated Interstitial Lung Disease: A Prospective Cohort Study
Authors: Sparks Jeffrey A. , He Xintong , Huang Jie , Fletcher Elaine A. , Zaccardelli Alessandra , Friedlander H. Maura , Gill Ritu R. , Hatabu Hiroto , Nishino Mizuki , Murphy David J. , Iannaccone Christine K. , Mahmoud Taysir G. , Frits Michelle L. , Lu Bing , Rosas Ivan O. , Dellaripa Paul F. , Weinblatt Michael E. , Karlson Elizabeth W. , Shadick Nancy A. , Doyle Tracy J.
Published: April 2019

Objective

To evaluate rheumatoid arthritis (RA) disease activity and risk of RA‐associated interstitial lung disease (RA‐ILD).

Methods

We investigated disease activity and risk of RA‐ILD using the Brigham RA Sequential Study (BRASS, 2003–2016). All patients were diagnosed as having RA according to accepted criteria. Disease Activity Scores in 28 joints (DAS28) and covariate data were measured prospectively at annual study visits. Diagnosis of RA‐ILD was determined by review of images from clinically indicated chest computed tomography scans. We analyzed patients without RA‐ILD at baseline. We used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for RA‐ILD, using annually updated DAS28 data, with adjustment for known RA‐ILD risk factors (age, sex, smoking status, RA duration, and serologic status). We performed alternative analyses that did not censor at the time of missing DAS28 data and included adjustment for use of methotrexate, use of glucocorticoids, presence of bone erosions, and presence of rheumatoid nodules.

Results

Among 1,419 participants, the mean ± SD age was 55.8 ± 14.2 years, and 68.6% were seropositive for either cyclic citrullinated peptide or rheumatoid factor. We identified 85 incident cases of RA‐ILD during a mean ± SD follow‐up duration of 8.9 ± 4.2 years per patient. The moderate/high disease activity group had a multivariable HR of 2.22 (95% CI 1.28–3.82) for RA‐ILD compared to the remission/low disease activity group. Risk of RA‐ILD increased across disease activity categories: multivariable HR 1.00 (reference) for remission, 1.41 (95% CI 0.61–3.28) for low disease activity, 2.08 (95% CI 1.06–4.05) for moderate disease activity, and 3.48 (95% CI 1.64–7.38) for high disease activity (P for trend = 0.001). For each unit increase in the DAS28, the risk of RA‐ILD increased by 35% (95% CI 14–60%). Results were similar in analyses that included follow‐up for missing DAS28 data and with adjustment for use of methotrexate, use of glucocorticoids, presence of bone erosions, or presence of rheumatoid nodules.

Conclusion

Active articular RA was associated with an increased risk of developing RA‐ILD. These results suggest that decreasing systemic inflammation may alter the natural history of RA‐ILD development.