bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radiopaque Highly Stiff and Tough Shape Memory Hydrogel Microcoils for Permanent Embolization of Arteries
Authors: Zhang Yinyu , Gao Haijun , Wang Hao , Xu Ziyang , Chen Xiaowei , Liu Bo , Shi Yuan , Lu Ying , Wen Lianfang , Li Yan , Li Zhisheng , Men Yongfeng , Feng Xuequan , Liu Wenguang 
Published: January 2018

AbstractTranscatheter arterial embolization of aneurysm with metal microcoils is notoriously prone to recanalization arising from the low filling ratio due to their extreme rigidity. Smart hydrogel microcoils with tunable modulus may essentially significantly improve the therapeutic efficacy. Here, a radiopaque highly stiff body‐temperature‐triggered shape memory (SM) hydrogel is fabricated for the first time by introducing reversible hydrophobic dipole pairing microdomains in the flexibly crosslinked network, followed by BaSO4 precipitation. This radiopacification does not affect their mechanical performances as well as the SM effect. It is demonstrated that the mechanical properties of SM hydrogels are comparable to those of rubbers and can be modulated by adjusting temperature ranging from 20 to 40 °C. Benefiting from the thermoresponsive mechanical properties, the stiff radiopaque hydrogel strip can easily pass through a catheter under the protection of cool saline for delivery into pig's renal artery, and spontaneously and rapidly transformed into a microcoil upon contacting blood. Real‐time angiogram reveals that continuous delivery of several hydrogel microcoils can efficiently occlude the blood supply. The kidneys are atrophied considerably over three month postoperative follow‐up, and no recanalization occurs throughout the experimental time. These novel hydrogel microcoils are promising to be developed as novel permanent embolic agents for treating aneurysm.
Coordinating Thermogel for Stem Cell Spheroids and Their Cyto‐Effectiveness
Authors: Ko Du Young , Patel Madhumita , Lee Hyun Jung , Jeong Byeongmoon 
Published: January 2018

AbstractA polymer (mP) with thermogelling and metal coordinating properties is prepared by pyridine‐dicarboxylate (PDC) connected poly(ethylene glycol)‐poly(propylene glycol)‐poly(ethylene glycol) triblock copolymers. Tonsil‐derived mesenchymal stem cells (TMSCs) are incorporated in the mP hydrogel by increasing the temperature of the cell‐suspended aqueous mP solution to 37 °C. The TMSCs are randomly embedded in the in situ formed hydrogel at first; however, they aggregated to form live cell spheroids on day 7. In contrast, the spheroid formation is blocked in the Fe3+‐incorporating mP thermogel. Compared with the conventional 2D‐cultured stem cells, the stem cell spheroid in the 3D mP culture system exhibits significantly enhanced stemness biomarkers, angiogenic biomarkers, and anti‐inflammatory biomarkers in the growth medium. In addition, the stem cell spheroid exhibits significantly greater biomarker expression for osteogenic, chondrogenic, and adipogenic differentiations than the stem cells cultured in the 2D system in each induction medium. This study suggests that a simple injection of stem cells suspended in the current aqueous mP solution can lead to the spontaneous formation of stem cell spheroids with excellent multipotency and retention in the in situ formed thermogel, and thus opens a direct injectable method for the application of the stem cells at a target site.
Porous Iron–Cobalt Alloy/Nitrogen‐Doped Carbon Cages Synthesized via Pyrolysis of Complex Metal–Organic Framework Hybrids for Oxygen Reduction
Authors: Guan Bu Yuan , Lu Yan , Wang Yong , Wu Minghong , Lou Xiong Wen (David) 
Published: January 2018

AbstractEfficient and stable nonprecious metal electrocatalysts for oxygen reduction are of great significance in some important electrochemical energy storage and conversion systems. As a unique class of porous hybrid materials, metal–organic frameworks (MOFs) and their composites are recently considered as promising precursors to derive advanced functional materials with controlled structures and compositions. Here, an “MOF‐in‐MOF hybrid” confined pyrolysis strategy is developed for the synthesis of porous Fe–Co alloy/N‐doped carbon cages. A unique “MOF‐in‐MOF hybrid” architecture constructed from a Zn‐based MOF core and a Co‐based MOF hybrid shell encapsulated with FeOOH nanorods is first prepared, followed by a pyrolysis process to obtain a cage‐shaped hybrid material consisting of Fe–Co alloy nanocrystallites evenly distributed inside a porous N‐doped carbon microshell. Of note, this strategy can be extended to synthesize many other multifunctional “nanosubstrate‐in‐MOF hybrid” core–shelled structures. Benefiting from the structural and compositional advantages, the as‐derived hybrid cages exhibit superior electrocatalytic performance for the oxygen reduction reaction in alkaline solution. The present approach may provide some insight in design and synthesis of complex MOF hybrid structures and their derived functional materials for energy storage and conversion applications.
Accelerated Discovery of Large Electrostrains in BaTiO3‐Based Piezoelectrics Using Active Learning
Authors: Yuan Ruihao , Liu Zhen , Balachandran Prasanna V. , Xue Deqing , Zhou Yumei , Ding Xiangdong , Sun Jun , Xue Dezhen , Lookman Turab 
Published: January 2018

AbstractA key challenge in guiding experiments toward materials with desired properties is to effectively navigate the vast search space comprising the chemistry and structure of allowed compounds. Here, it is shown how the use of machine learning coupled to optimization methods can accelerate the discovery of new Pb‐free BaTiO3 (BTO‐) based piezoelectrics with large electrostrains. By experimentally comparing several design strategies, it is shown that the approach balancing the trade‐off between exploration (using uncertainties) and exploitation (using only model predictions) gives the optimal criterion leading to the synthesis of the piezoelectric (Ba0.84Ca0.16)(Ti0.90Zr0.07Sn0.03)O3 with the largest electrostrain of 0.23% in the BTO family. Using Landau theory and insights from density functional theory, it is uncovered that the observed large electrostrain is due to the presence of Sn, which allows for the ease of switching of tetragonal domains under an electric field.
Atomic Layer Deposition of Rhenium Disulfide
Authors: Hämäläinen Jani , Mattinen Miika , Mizohata Kenichiro , Meinander Kristoffer , Vehkamäki Marko , Räisänen Jyrki , Ritala Mikko , Leskelä Markku 
Published: January 2018

Abstract2D materials research is advancing rapidly as various new “beyond graphene” materials are fabricated, their properties studied, and materials tested in various applications. Rhenium disulfide is one of the 2D transition metal dichalcogenides that has recently shown to possess extraordinary properties such as that it is not limited by the strict monolayer thickness requirements. The unique inherent decoupling of monolayers in ReS2 combined with a direct bandgap and highly anisotropic properties makes ReS2 one of the most interesting 2D materials for a plethora of applications. Here, a highly controllable and precise atomic layer deposition (ALD) technique is applied to deposit ReS2 thin films. Film growth is demonstrated on large area (5 cm × 5 cm) substrates at moderate deposition temperatures between 120 and 500 °C, and the films are extensively characterized using field emission scanning electron microscopy/energy‐dispersive X‐ray spectroscopy, X‐ray diffractometry using grazing incidence, atomic force microscopy, focused ion beam/transmission electron microscopy, X‐ray photoelectron spectroscopy, and time‐of‐flight elastic recoil detection analysis techniques. The developed ReS2 ALD process highlights the potential of the material for applications beyond planar structure architectures. The ALD process also offers a route to an upgrade to an industrial scale.
Inductor‐Free Wireless Energy Delivery via Maxwell's Displacement Current from an Electrodeless Triboelectric Nanogenerator
Authors: Cao Xia , Zhang Meng , Huang Jinrong , Jiang Tao , Zou Jingdian , Wang Ning , Wang Zhong Lin 
Published: January 2018

AbstractWireless power delivery has been a dream technology for applications in medical science, security, radio frequency identification (RFID), and the internet of things, and is usually based on induction coils and/or antenna. Here, a new approach is demonstrated for wireless power delivery by using the Maxwell's displacement current generated by an electrodeless triboelectric nanogenerator (TENG) that directly harvests ambient mechanical energy. A rotary electrodeless TENG is fabricated using the contact and sliding mode with a segmented structure. Due to the leakage of electric field between the segments during relative rotation, the generated Maxwell's displacement current in free space is collected by metal collectors. At a gap distance of 3 cm, the output wireless current density and voltage can reach 7 µA cm−2 and 65 V, respectively. A larger rotary electrodeless TENG and flexible wearable electrodeless TENG are demonstrated to power light‐emitting diodes (LEDs) through wireless energy delivery. This innovative discovery opens a new avenue for noncontact, wireless energy transmission for applications in portable and wearable electronics.
Conformal Nanocoatings with Uniform and Controllable Thickness on Microstructured Surfaces: A General Assembly Route
Authors: Hou Yi , Wang Zhen , Cai Chao , Hao Xi , Li Dongdong , Zhao Ning , Zhao Yiping , Chen Li , Ma Hongwei , Xu Jian 
Published: January 2018

AbstractAssembling nanoparticles (NPs) on various surfaces are intensively investigated for the construction of functional nanocoatings; however, it is still a challenge to fabricate conformal nanocoatings uniformly on surfaces having micro‐ or nanostructures. Herein, it is demonstrated that the negatively charged SiO2 NPs and the positively charged silicon coupling agent can be assembled layer‐by‐layer on the microstructures based on the combination of electrostatic interaction and condensation reaction. Conformal nanocoatings with controllable thickness are formed on the microstructured surfaces with different compositions and morphologies. The formation mechanism is confirmed by using quartz crystal microbalance with dissipation (QCM‐D) to study the assembly process in real time. The universality of this method is illustrated by using other reactive building blocks with opposite charge to build up the conformal nanocoatings. Application in the preparation of antireflective nanocoatings on nonplanar optical materials is demonstrated. This simple, versatile, and scalable strategy for the preparation of conformal nanocoatings is promising for practical applications.
An Unusual Strong Visible‐Light Absorption Band in Red Anatase TiO2 Photocatalyst Induced by Atomic Hydrogen‐Occupied Oxygen Vacancies
Authors: Yang Yongqiang , Yin Li‐Chang , Gong Yue , Niu Ping , Wang Jian‐Qiang , Gu Lin , Chen Xingqiu , Liu Gang , Wang Lianzhou , Cheng Hui‐Ming 
Published: January 2018

AbstractIncreasing visible light absorption of classic wide‐bandgap photocatalysts like TiO2 has long been pursued in order to promote solar energy conversion. Modulating the composition and/or stoichiometry of these photocatalysts is essential to narrow their bandgap for a strong visible‐light absorption band. However, the bands obtained so far normally suffer from a low absorbance and/or narrow range. Herein, in contrast to the common tail‐like absorption band in hydrogen‐free oxygen‐deficient TiO2, an unusual strong absorption band spanning the full spectrum of visible light is achieved in anatase TiO2 by intentionally introducing atomic hydrogen‐mediated oxygen vacancies. Combining experimental characterizations with theoretical calculations reveals the excitation of a new subvalence band associated with atomic hydrogen filled oxygen vacancies as the origin of such band, which subsequently leads to active photo‐electrochemical water oxidation under visible light. These findings could provide a powerful way of tailoring wide‐bandgap semiconductors to fully capture solar light.
Printable Transparent Conductive Films for Flexible Electronics
Authors: Li Dongdong , Lai Wen‐Yong , Zhang Yi‐Zhou , Huang Wei 
Published: January 2018

AbstractPrinted electronics are an important enabling technology for the development of low‐cost, large‐area, and flexible optoelectronic devices. Transparent conductive films (TCFs) made from solution‐processable transparent conductive materials, such as metal nanoparticles/nanowires, carbon nanotubes, graphene, and conductive polymers, can simultaneously exhibit high mechanical flexibility, low cost, and better photoelectric properties compared to the commonly used sputtered indium‐tin‐oxide‐based TCFs, and are thus receiving great attention. This Review summarizes recent advances of large‐area flexible TCFs enabled by several roll‐to‐roll‐compatible printed techniques including inkjet printing, screen printing, offset printing, and gravure printing using the emerging transparent conductive materials. The preparation of TCFs including ink formulation, substrate treatment, patterning, and postprocessing, and their potential applications in solar cells, organic light‐emitting diodes, and touch panels are discussed in detail. The rational combination of a variety of printed techniques with emerging transparent conductive materials is believed to extend the opportunities for the development of printed electronics within the realm of flexible electronics and beyond.
Near‐Infrared Upconversion Mesoporous Cerium Oxide Hollow Biophotocatalyst for Concurrent pH‐/H2O2‐Responsive O2‐Evolving Synergetic Cancer Therapy
Authors: Yao Chi , Wang Wenxing , Wang Peiyuan , Zhao Mengyao , Li Xiaomin , Zhang Fan 
Published: January 2018

AbstractTumor hypoxia is typically presented in the central region of solid tumors, which is mainly caused by an inadequate blood flow and oxygen supply. In the conventional treatment of hypoxic human tumors, not only the oxygen‐dependent photodynamic therapy (PDT), but also antitumor drug‐based chemotherapy, is considerably limited. The use of direct oxygen delivering approach with oxygen‐dependent PDT or chemotherapy may potentiate the reactive oxygen species (ROS)‐mediated cytotoxicity of the drug toward normal tissues. Herein, a synergetic one‐for‐all mesoporous cerium oxide upconversion biophotocatalyst is developed to achieve intratumorally endogenous H2O2‐responsive self‐sufficiency of O2 and near‐infrared light controlled PDT simultaneously for overcoming hypoxia cancer. Furthermore, the sufficient O2 plays an important role in overcoming the chemotherapeutic drug‐resistant cancer caused by hypoxia, therefore inducing tumor cell apoptosis significantly.
Activatable Protein Nanoparticles for Targeted Delivery of Therapeutic Peptides
Authors: Yu Xi , Gou Xingchun , Wu Peng , Han Liang , Tian Daofeng , Du Fengyi , Chen Zeming , Liu Fuyao , Deng Gang , Chen Ann T. , Ma Chao , Liu Jun , Hashmi Sara M. , Guo Xing , Wang Xiaolong , Zhao Haitian , Liu Xinran , Zhu Xudong , Sheth Kevin , Chen Qianxue , Fan Louzhen , Zhou Jiangbing 
Published: January 2018

AbstractClinical translation of therapeutic peptides, particularly those that require penetration of the cell membrane or are cytolytic, is a major challenge. A novel approach based on a complementary mechanism, which has been widely used for guided synthesis of DNA or RNA nanoparticles, for de novo design of activatable protein nanoparticles (APNPs) for targeted delivery of therapeutic peptides is described. APNPs are formed through self‐assembly of three independent polypeptides based on pairwise coiled‐coil dimerization. They are capable of long circulation in the blood and can be engineered to target diseases. Peptides to be delivered are incorporated into APNPs and released into the disease microenvironment by locally enriched proteases. It is demonstrated that APNPs mediate efficient delivery of NR2B9c, a neuroprotective peptide that functions after cell penetration, and melittin, a cytolytic peptide that perturbs the lipid bilayer, for effective treatment of stroke and cancer, respectively. Due to their robust properties, simple design, and economic costs, APNPs have great potential to serve as a versatile platform for controlled delivery of therapeutic peptides.
An Artificial Flexible Visual Memory System Based on an UV‐Motivated Memristor
Authors: Chen Shuai , Lou Zheng , Chen Di , Shen Guozhen 
Published: January 2018

AbstractFor the mimicry of human visual memory, a prominent challenge is how to detect and store the image information by electronic devices, which demands a multifunctional integration to sense light like eyes and to memorize image information like the brain by transforming optical signals to electrical signals that can be recognized by electronic devices. Although current image sensors can perceive simple images in real time, the image information fades away when the external image stimuli are removed. The deficiency between the state‐of‐the‐art image sensors and visual memory system inspires the logical integration of image sensors and memory devices to realize the sensing and memory process toward light information for the bionic design of human visual memory. Hence, a facile architecture is designed to construct artificial flexible visual memory system by employing an UV‐motivated memristor. The visual memory arrays can realize the detection and memory process of UV light distribution with a patterned image for a long‐term retention and the stored image information can be reset by a negative voltage sweep and reprogrammed to the same or an other image distribution, which proves the effective reusability. These results provide new opportunities for the mimicry of human visual memory and enable the flexible visual memory device to be applied in future wearable electronics, electronic eyes, multifunctional robotics, and auxiliary equipment for visual handicapped.
Triboelectric Nanogenerator Tree for Harvesting Wind Energy and Illuminating in Subway Tunnel
Authors: Bian Yaoxing , Jiang Tao , Xiao Tianxiao , Gong Wenping , Cao Xia , Wang Zhaona , Wang Zhong Lin 
Published: January 2018

AbstractAs an important green energy in our life, natural wind energy is widely applied to generate electricity. In this work, a bionic triboelectric nanogenerator tree composed of supercells with cell I of leaf and cell II of stem is designed for harvesting wind energy by utilizing the coupling effect of contact electrification and electrostatic induction. At the wind speed of 11 m s−1, the fabricated triboelectric nanogenerator tree produces an open‐circuit voltage of 330 V and a short‐circuit current of 59.6 µA. The corresponding output power is 3.6 mW at the matched resistance of 60 MΩ, and 145 light‐emitting diodes can be lightened. Furthermore, a flexible device of a triboelectric nanogenerator tree is fabricated to present potential applications for illumination and advertisement in the long tunnel through harvesting the moving‐generated wind energy. Due to the advantages of light weight, low cost, easy fabrication, and beautiful appearance, the triboelectric nanogenerator tree can find important applications in billboard illuminating, vehicle speed measuring, and so on.
How Does the Neighborhood “Come through the Door?” Concentrated Disadvantage, Residential Instability, and the Home Environment for Preschoolers
Authors: May Emily M. , Azar Sandra T. , Matthews Stephen A. 
Published: January 2018

AbstractLiving in a disadvantaged neighborhood is associated with heightened risk for poor school readiness and health outcomes in early childhood, and the home environment is thought to be a primary mechanism by which neighborhood context impacts preschoolers. This study examined the effects of neighborhood concentrated disadvantage and neighborhood residential instability on the home physical environment and home learning environment for preschoolers in economically disadvantaged families (N = 187). Using structural equation modeling, mothers' perceived neighborhood disorder and depressive symptoms were examined as mechanisms by which neighborhood context “comes through the door.” Mothers' neighborhood social embeddedness was also explored as a protective factor. Results showed that concentrated disadvantage was negatively associated with the quality of the home physical environment, and residential instability was negatively associated with the quality of the home learning environment. Concentrated disadvantage had an indirect effect on the home learning environment through mothers' perceived neighborhood disorder and depressive symptoms. The effects of concentrated disadvantage on the home environment were buffered by mothers' neighborhood social embeddedness. Study findings advance understanding of socioeconomic‐ and place‐based disparities in developmental outcomes and identify potential targets for interventions aimed at lessening effects of neighborhood disadvantage on families with young children.
Biopolymer‐Aerogele und ‐Schäume: Chemie, Eigenschaften und Anwendungen
Authors: Zhao Shanyu , Malfait Wim J. , Guerrero‐Alburquerque Natalia , Koebel Matthias M. , Nyström Gustav 
Published: January 2018

AbstractBiopolymer‐Aerogele gehören zu den ersten Aerogelen, die hergestellt wurden, aber erst im letzten Jahrzehnt kam es zu einer Belebung der Forschung über Biopolymer‐ und Biopolymer‐Verbundstoff‐Aerogele, die durch Fragen der Nachhaltigkeit, einstellbare spezielle Eigenschaften und einfache Funktionalisierung motiviert wird. Biopolymer‐Aerogele und offenzellige Biopolymer‐Schäume haben Potenzial für klassische Aerogel‐Anwendungen wie Wärmedämmung und neue Anwendungen bei der Filtration, Öl‐Wasser‐Trennung, CO2‐Abscheidung, Katalyse und in der Medizin. Das Gebiet der Biopolymer‐Aerogele wird heute von der empirischen Materialentwicklung auf dem Labormaßstab beherrscht und benötigt eine bessere theoretische Grundlage und Test in Pilotanlagen. Unser Aufsatz umfasst eine Datenbank mit über 3800 Biopolymer‐Aerogel‐Eigenschaften, beurteilt den Forschungsstand auf dem Gebiet und diskutiert wissenschaftliche, technologische und wirtschaftliche Hindernisse bei der Kommerzialisierung dieser faszinierenden Materialien.
Selective Production of Renewable para‐Xylene by Tungsten Carbide Catalyzed Atom‐Economic Cascade Reactions
Authors: Dai Tao , Li Changzhi , Li Lin , Zhao Zongbao Kent , Zhang Bo , Cong Yu , Wang Aiqin 
Published: January 2018

AbstractTungsten carbide was employed as the catalyst in an atom‐economic and renewable synthesis of para‐xylene with excellent selectivity and yield from 4‐methyl‐3‐cyclohexene‐1‐carbonylaldehyde (4‐MCHCA). This intermediate is the product of the Diels–Alder reaction between the two readily available bio‐based building blocks acrolein and isoprene. Our results suggest that 4‐MCHCA undergoes a novel dehydroaromatization–hydrodeoxygenation cascade process by intramolecular hydrogen transfer that does not involve an external hydrogen source, and that the hydrodeoxygenation occurs through the direct dissociation of the C=O bond on the W2C surface. Notably, this process is readily applicable to the synthesis of various (multi)methylated arenes from bio‐based building blocks, thus potentially providing a petroleum‐independent solution to valuable aromatic compounds.