bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optogenetically Controlled TrkA Activity Improves the Regenerative Capacity of Hair‐Follicle‐Derived Stem Cells to Differentiate into Neurons and Glia
Authors: Huang Taida , Zhang Yan , Wang Zitian , Zeng Yunxin , Wang Nan , Fan Huaxun , Huang Zhangsen , Su Yixun , Huang Xiaomin , Chen Hui , Zhang Kai , Yi Chenju 
Published: September 2020

AbstractHair‐follicle‐derived stem cells (HSCs) originating from the bulge region of the mouse vibrissa hair follicle are able to differentiate into neuronal and glial lineage cells. The tropomyosin receptor kinase A (TrkA) receptor that is expressed on these cells plays key roles in mediating the survival and differentiation of neural progenitors as well as in the regulation of the growth and regeneration of different neural systems. In this study, the OptoTrkA system is introduced, which is able to stimulate TrkA activity via blue‐light illumination in HSCs. This allows to determine whether TrkA signaling is capable of influencing the proliferation, migration, and neural differentiation of these somatic stem cells. It is found that OptoTrkA is able to activate downstream molecules such as ERK and AKT with blue‐light illumination, and subsequently able to terminate this kinase activity in the dark. HSCs with OptoTrkA activity show an increased ability for proliferation and migration and also exhibited accelerated neuronal and glial cell differentiation. These findings suggest that the precise control of TrkA activity using optogenetic tools is a viable strategy for the regeneration of neurons from HSCs, and also provides a novel insight into the clinical application of optogenetic tools in cell‐transplantation therapy.
Chiral Cellulose Nanocrystals with Intercalated Amorphous Polysaccharides for Controlled Iridescence and Enhanced Mechanics
Authors: Adstedt Katarina , Popenov Elizabeth A. , Pierce Kellina J. , Xiong Rui , Geryak Ren , Cherpak Vladyslav , Nepal Dhriti , Bunning Timothy J. , Tsukruk Vladimir V. 
Published: September 2020

AbstractA unique case of combined enhanced mechanical performance and tunable structural color for chiral composites from cellulose nanocrystals (CNCs) arises by adding nanofibrillar wood‐derived polymers with similar chemical compositions. When amorphous polysaccharides (pullulan, dextran, and xylan) are added, they intercalate seamlessly into the original helicoidal organization via interstitial volumes within nanocrystals and between nematic monolayers. The polysaccharides fill the available free volume in between packed nanocrystals until 40 wt% content is reached, with no phase separation occurring. Due to the inter‐nanocrystal intercalation, these natural polysaccharide–cellulose composites show a nearly twofold increase in toughness and modulus. Beyond improved mechanics, the preserved iridescence shows a dramatic red shift from blue to near‐infrared region, expanding the initial pitch length without disturbing the long‐range chiral ordering. In the mechanistic model suggested here, the individual backbones first form intercalated morphologies in the interstitial volumes between tightly packed nanocrystals. After this, the polysaccharides form a monolayer, and eventually double layer, between nanocrystal monolayers, thus incrementally “unwinding” initial chiral organization. The resulting CNC–polysaccharide films maintain their vivid iridescence with broad color appearance and are among the first entirely biobased composites to maintain iridescence with improved mechanics.
Probing Antiferroelectric‐Ferroelectric Phase Transitions in PbZrO3 Capacitors by Piezoresponse Force Microscopy
Authors: Lu Haidong , Glinsek Sebastjan , Buragohain Pratyush , Defay Emmanuel , Iñiguez Jorge , Gruverman Alexei 
Published: September 2020

AbstractFunctional characterization of antiferroelectric (AFE) materials typically involves macroscopic testing of their nonlocal integrated information on their dielectric properties, such as polarization hysteresis loops, field‐dependent strain, and capacitance while the local AFE properties have been rarely addressed. Here, a new protocol is demonstrated for local probing of the antiferroelectric/ferroelectric (AFE/FE) phase transition in PbZrO3 capacitors by piezoresponse force microscopy (PFM). PFM spectroscopy of the local AFE/FE phase transition parameters is performed and their spatial variability via two‐dimensional mapping is investigated. It is shown that AFE hysteresis loops recorded by PFM in the bias‐on regime exhibit four characteristic amplitude peaks. Within the framework of Landau theory, these features are attributed to a considerable increase in the electromechanical strain response due to the dielectric constant divergence during AFE/FE phase transitions. The proposed approach can be used to differentiate between the antiferroelectric and nonpolar dielectric phases in functional devices using the electrically induced polarization.
Multilevel Nonvolatile Memcapacitance in Graphene‐Silk Fibroin Biocomposite Paper
Authors: Guo Xin , Huang Lei , Zhou Xinge , Chang Quanhong , Cao Changying , Xiao Guina , Shi Wangzhou 
Published: September 2020

AbstractThe demand for flexible memory devices is growing due to the development of flexible neuromorphic electronics for wearable devices, soft robotics, and biologically‐inspired circuits. Described herein is a flexible memcapacitor based on a biocomposite paper composed of reduced graphene oxide (rGO) and silk fibroin (SF) via a gel‐film transformation process. The presented rGO‐SF/H3PO4‐polyvinyl alcohol (PVA)/rGO memory stack exhibits analog, reversible, and nonvolatile memcapacitance characteristics. Impressively, the stack has a broad range of high capacitance states so as to be tuned to at least four capacitive states by the operating voltages. This memcapacitive behavior is ascribed to an interfacial charge build‐up (capacitive double layer) modulated by the H+ migration, which is trapped/detrapped by the rGO‐SF paper depending on bias conditions. Further, the flexibility tests are conducted to confirm the applicability of the rGO‐SF/H3PO4‐PVA/rGO stack to flexible devices. Thus, the rGO‐SF papers can be used as electronic materials for capacitive memory in neuromorphic systems where operation at biocompatibility, low‐energy, and mechanical flexibility are important issues.
Bioelectronics‐Related 2D Materials Beyond Graphene: Fundamentals, Properties, and Applications
Authors: Wang Bolun , Sun Yufei , Ding Hanyuan , Zhao Xuan , Zhang Lei , Bai Jingwei , Liu Kai 
Published: September 2020

AbstractThe rapid development of bioelectronics has lead to the emergence of versatile biorelated architectures for information processing systems, sensors, actuators, and wearable devices. In recent years, 2D materials beyond graphene have been demonstrated to be essential bioelectronic device components owing to their merits of atomic thickness, high transparency, large specific area, unique electrical/optical properties, and good biocompatibility. Herein, the recent advances in the bioelectronic applications of 2D materials beyond graphene are reviewed and their physicochemical properties, biocompatibility, synthesis, and processing methods are described. Moreover, the design strategies, working mechanisms, and performances of various bioelectronic devices based on these materials are summarized and the perspectives and challenges of this research field are highlighted. Thus, this review is expected to inspire new insights and technical advances for future research.
Phonon‐Enhanced Near‐Field Spectroscopy to Extract the Local Electronic Properties of Buried 2D Electron Systems in Oxide Heterostructures
Authors: Barnett Julian , Rose Marc‐André , Ulrich Georg , Lewin Martin , Kästner Bernd , Hoehl Arne , Dittmann Regina , Gunkel Felix , Taubner Thomas 
Published: September 2020

AbstractIn the family of functional oxide materials, the interface between LaAlO3 and SrTiO3 (LAO/STO) is an interesting example, as both materials are large‐bandgap insulators in their bulk state but give rise to a confined 2D electron gas (2DEG) when combined through thin‐film deposition. While this 2DEG exhibits remarkable properties, its experimental investigation is mostly limited to destructive or non‐local (i.e. averaging over larger areas) methods until recently. Scanning near‐field optical microscopy is shown to overcome this limitation, detecting buried 2DEGs by using highly confined optical near‐fields. Here, a full spectroscopic approach with phonon‐enhancement and simulations based on the finite dipole model is combined to extract quantitative electronic properties of the interfacial LAO/STO 2DEG. This threefold improvement compared to previous work will enable the quantitative nanoscale, non‐destructive, sub‐surface analysis of complex oxide thin films and interfaces, as well as similar heterostructures.
Resolving Donor–Acceptor Interfaces and Charge Carrier Energy Levels of Organic Semiconductors with Polar Side Chains
Authors: Alessandri Riccardo , Sami Selim , Barnoud Jonathan , de Vries Alex H. , Marrink Siewert J. , Havenith Remco W. A. 
Published: September 2020

AbstractOrganic semiconductors consisting of molecules bearing polar side chains have been proposed as potential candidates to overcome the limitations of organic photovoltaics owing to their enhanced dielectric constant. However, introducing such polar molecules in photovoltaic devices has not yet resulted in higher efficiencies. A microscopic understanding of the impact of polar side chains on electronic and structural properties of organic semiconductors is paramount to rationalize their effect. Here, the impact of such side chains on bulk heterojunction overall morphology, molecular configurations at donor–acceptor (DA) interfaces, and charge carrier energy levels is investigated. The multiscale modeling approach used allows to resolve DA interfaces with atomistic resolution while taking into account the large‐scale self‐organization process which takes place during the processing of an organic thin film. The polar fullerene‐based blends are compared to the well‐studied reference system, poly(3‐hexyl‐thiophene) (P3HT):phenyl‐C61‐butyric acid methyl ester (PCBM). Introduction of polar side chains on a similar molecular scaffold does not affect molecular orientations at the DA interfaces; such orientations are, however, found to be affected by processing conditions and polymer molecular weight. Polar side chains, instead, are found to impact considerably the charge carrier energy levels of the organic blend, causing electrostatic‐induced broadening of these levels.
Molecular Functionalization of Chemically Active Defects in WSe2 for Enhanced Opto‐Electronics
Authors: Zhao Yuda , Gali Sai Manoj , Wang Can , Pershin Anton , Slassi Amine , Beljonne David , Samorì Paolo 
Published: September 2020

AbstractStructural defects are known to worsen electrical and optical properties of 2D materials. Transition metal dichalcogenides (TMDs) are prone to chalcogen vacancies and molecular functionalization of these vacancies offers a powerful strategy to engineer the crystal structure by healing such defects. This molecular approach can effectively improve physical properties of 2D materials and optimize the performance of 2D electronic devices. While this strategy has been successfully exploited to heal vacancies in sulfides, its viability on selenides based TMDs has not yet been proven. Here, by using thiophenol molecules to functionalize monolayer WSe2 surface containing Se vacancies, it is demonstrated that the defect healing via molecular approach not only improves the performance of WSe2 transistors (> tenfold increase in the current density, the electron mobility, and the Ion/Ioff ratio), but also enhances the photoluminescence properties of monolayer WSe2 flakes (threefold increase of photoluminescence intensity at room temperature). Theoretical calculations elucidate the mechanism of molecular passivation, which originates from the strong interaction between thiol functional group at Se vacancy sites and neighboring tungsten atoms. These results demonstrate that the molecular approach represents a powerful strategy to engineer WSe2 transistors and optimize their optical properties, paving the way toward high‐performance 2D (opto)electronic devices.
Self‐Regulating Organic Polymer Coupled with Enlarged Inorganic SnS2 Interlamellar Composite for Potassium Ion Batteries
Authors: Qin Guohui , Liu Yuting , Han Pinyu , Wang Liying , Liu Fusheng , Ma Jianmin 
Published: September 2020

AbstractTin (Sn)‐based alloy SnS2 has attracted significant attention as a promising candidate for potassium ion storage due to the high theoretical capacity, however, it seriously suffers from the huge volume variation and the growth of potassium dendrites during the repeated cycling process. Herein, hierarchical polyaspartic acid (PASP) modified SnS2 nanosheets embedded into hollow N doped carbon fibers (CN) derived from setaria glauca (PASP@SnS2@CN) are fabricated for potassium storage. PASP cross‐linkers provide the enlarged interlamellar spacing of 6.8 Å (against 5.9 Å for the pristine SnS2), the higher ion transportation channels as well as the self‐regulating dendrite‐free K plating. Consequently, a high reversible capacity (564 mAh g−1 at 50 mA g−1) and a prominent rate performance of 273 mAh g−1 at 2 A g−1 are delivered. Both the experimental data and computational models confirm that a thin and robust solid electrolyte interface (SEI) layer is formed over the dendrite free PASP@SnS2@CN due to the strong interactions (K–N and H+/K+ proton exchange) between the PASP and the electrolyte (KFSI). The deformable and self‐ regulating organic–inorganic configuration is promising for the basis construction of transition metals, has practical applications for K storage.
Interweaved Cellular Structured Ceramic Nanofibrous Aerogels with Superior Bendability and Compressibility
Authors: Dou Lvye , Zhang Xinxin , Shan Haoru , Cheng Xiaota , Si Yang , Yu Jianyong , Ding Bin 
Published: September 2020

AbstractCeramic aerogels are attractive candidates for thermal insulation systems in spaceships, missiles, and aircrafts. However, the general lack of mechanical stability in conventional ceramic aerogels presents a major challenge for their practical applications. To date, the creation of mechanically robust ceramic aerogels has not made significant progress. Herein, a universal strategy is presented to fabricate ceramic nanofibrous aerogels with both superior bendability and compressibility, by assembling flexible silica nanofibers with a high length‐to‐diameter ratio into a highly continuous interwoven cellular structure. The resulting aerogels, with improved structural continuity, exhibit enhanced mechanical properties including large compression and buckling strain recovery (85%), temperature‐invariant superelasticity (from −196 °C to 1100 °C), and robust fatigue tolerance up to 100 000 cycles. In parallel, the low thermal conductivity (0.0223 W m−1 K−1), as well as exceptional high‐temperature thermal insulation performance enable them to be ideal candidates for thermal insulation in extreme environments. The successful synthesis of this material may shed light on the development of other mechanically robust ceramic aerogels.
Redox‐Responsive Self‐Assembled Nanoparticles for Cancer Therapy
Authors: Li Dandan , Zhang Ruhe , Liu Guiting , Kang Yang , Wu Jun 
Published: September 2020

AbstractChemotherapy, combined with other treatments, is widely applied in the clinical treatment of cancer. However, deficiencies inherited from the traditional route of administration limit its successful application. With the development of nanotechnology, a series of smart nanodelivery systems have been developed to utilize the unique tumor environment (pH changes, different enzymes, and redox potential gradients) and exogenous stimuli (thermal changes, magnetic fields, and light) to improve the curative effect of anticancer drugs. In this review, endogenous and exogenous stimuli are briefly introduced. Among these stimuli, various redox‐sensitive linkages are primarily described in detail, and their application with self‐assembled nanoparticles is recounted. Finally, the application of redox‐responsive self‐assembled nanoparticles in cancer therapy is summarized.
Past, Present, and Future of Soft‐Tissue Prosthetics: Advanced Polymers and Advanced Manufacturing
Authors: Powell Sean K. , Cruz Rena L. J. , Ross Maureen T. , Woodruff Maria A. 
Published: September 2020

AbstractMillions of people worldwide experience disfigurement due to cancers, congenital defects, or trauma, leading to significant psychological, social, and economic disadvantage. Prosthetics aim to reduce their suffering by restoring aesthetics and function using synthetic materials that mimic the characteristics of native tissue. In the 1900s, natural materials used for thousands of years in prosthetics were replaced by synthetic polymers bringing about significant improvements in fabrication and greater realism and utility. These traditional methods have now been disrupted by the advanced manufacturing revolution, radically changing the materials, methods, and nature of prosthetics. In this report, traditional synthetic polymers and advanced prosthetic materials and manufacturing techniques are discussed, including a focus on prosthetic material degradation. New manufacturing approaches and future technological developments are also discussed in the context of specific tissues requiring aesthetic restoration, such as ear, nose, face, eye, breast, and hand. As advanced manufacturing moves from research into clinical practice, prosthetics can begin new age to significantly improve the quality of life for those suffering tissue loss or disfigurement.
Pillar[n]arene‐Based Supramolecular Switches in Solution and on Surfaces
Authors: Lou Xin‐Yue , Yang Ying‐Wei 
Published: September 2020

AbstractThe design and synthesis of new synthetic macrocycles has driven the rapid development of supramolecular chemistry and materials. Pillar[n]arenes, as a new type of macrocyclic compounds, are used as a promising type of building blocks for switchable supramolecular systems due to their versatile functionalization and the ability of binding toward various guest molecules. A number of guests can form inclusion complexes with pillar[n]arenes and their derivatives in solution, which are sensitive to different external triggers. Interestingly, the pursuit of complex stimuli‐responsive functional materials and devices has largely motivated the shift of pillar[n]arene‐based switches from solution media to surfaces for controllable macroscopic motions on solid platforms. Facilitated by the facile modification of pillar[n]arenes on various solid supports and the dynamic binding of host–guest complexes, numerous functional hybrid materials with adjustable physical or chemical properties and integrated functionalities have been reported in the last decade. Here, the advance of supramolecular switches in solution and on surfaces based on pillar[n]arenes and derivatives with an emphasis on the efforts and the latest contributions from the field is discussed.
The Application of Dual‐Layer, Mussel‐Inspired, Antifouling Polyglycerol‐Based Coatings in Ventricular Assist Devices
Authors: Kulka Michaël W. , Smatty Sarah , Hehnen Felix , Bierewirtz Tim , Silberreis Kim , Nie Chuanxiong , Kerkhoff Yannic , Grötzinger Carsten , Friedrich Sebastian , Dahms Lars Ingemar , Dernedde Jens , Grunwald Ingo , Schirner Michael , Kertzscher Ulrich , Affeld Klaus , Haag Rainer 
Published: September 2020

AbstractContinuous‐flow ventricular assist devices (VADs) have established themselves as a lifesaving therapy option in patients with severe cardiovascular disease. Unfortunately, complications with VADs resulting from the shear‐induced formation of surface blood clots are common. In the current work, an antifouling coating based on the combination of mussel‐inspired dendritic polyglycerol (MI‐dPG) and linear polyglycerol (lPG) is tested for its cell‐repelling properties, biocompatibility, and complement activating properties. Furthermore, the adhesion and activation of blood platelets are tested under static and flow conditions. The adhesion and proliferation of two cell types are studied by means of LIVE/DEAD cell staining, and it is clearly observed that the lPG‐functionalized MI‐dPG coating prevents cell adhesion. Additionally, no cell mortality is observed on all substrates, indicating the biocompatibility of the tested coatings. All coatings show lower (or equal) complement‐activating properties than bare titanium, which is considered a highly biocompatible material. Most importantly, the lPG‐functionalized system prevents the adhesion and activation of blood platelets under static and flow conditions. Finally, a prototype VAD is successfully coated with MI‐dPG under flow conditions. In the current study, the efficient lPG‐functionalization of the MI‐dPG coating is proved to obtain cell‐ and platelet‐repelling surfaces.
Highly Robust, Pressure‐Resistant Superhydrophobic Coatings from Monolayer Assemblies of Chained Nanoparticles
Authors: Wu Gaoxiang , Zhao Yiping , Ge Dengteng , Zhao Yubo , Yang Lili , Yang Shu 
Published: September 2020

AbstractDespite significant progresses in development of superhydrohpobic coatings, their ability to resist small water droplets, which can exert large Laplace pressure on surface, remain limited. Here, a new strategy by self‐assembly of a monolayer of chained silica nanoparticles, forming an ultrathin film (<100 nm) with two‐tiered nanoasperity is presented. The resulting coating shows ultrahigh water repellency and high visible transparency. It can also repel low surface energy liquids, such as alcohol/water mixtures (surface tension ≥42 mN m−1). Importantly, the superhydrophobic coating demonstrates high resistance to impact pressure (at least 250 Pa) from water droplets dropped from 3.3 m height and internal Laplace pressure of 15 kPa from evaporated water droplets. Furthermore, the CNP coating remains to be superhydrophobic with condensed water droplets radius as small as 0.3 mm even after condensation for 6 h. In comparison, all of these properties are not possible from the assembly of spherical nanoparticles.
Aggregation‐Induced Emission Luminogens for Direct Exfoliation of 2D Layered Materials in Ethanol
Authors: Zhao Yu , Gao Wei , Yang Yibin , Zhang Haoke , Redshaw Carl , Feng Xing , Li Jingbo , Lam Jacky W. Y. , Tang Ben Zhong 
Published: September 2020

AbstractAggregation‐induced emission (AIE) luminogens are an important type of advanced functional materials with fantastic optical properties and have found potential applications in organic electronics, biochemistry, and molecular imaging. Herein, this article presents a novel application of AIE luminogens (AIEgens) for efficient exfoliation of layered transition metal dichalcogenides (TMDs, such as MoS2 and WSe2). From the 1H NMR spectroscopic analysis, the designed AIEgens can insert into the space between layers of MoS2 in ethanol solution and the dynamic molecular rotation against the weak interactions affords large‐scale few‐layer MoS2 nanosheets (7–8 layers) with enhanced smoothness. The 3D AIEgens play a significant role in preserving the crystal lattice of MoS2 even at high pressure (>15 GPa). More importantly, the new approach can also be used for exfoliation of WSe2 to achieve large‐scale few‐layer nanosheets. The present work thus provides a facile and high yielding synthetic method for accessing on a large scale 2D layered materials with enhanced properties for high‐technology applications.