bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fabricating MnO2 Nanozymes as Intracellular Catalytic DNA Circuit Generators for Versatile Imaging of Base‐Excision Repair in Living Cells
Authors: Chen Feng , Bai Min , Cao Ke , Zhao Yue , Wei Jing , Zhao Yongxi 
Published: October 2017

AbstractNanomaterial/DNA integrated systems have become an emerging tool for intracellular imaging. However, intracellular catalytic DNA circuit is rarely explored. Commonly used nanosystems neglect intracellular DNA assembly, conformation folding and catalytic efficiency, all demanding appropriate metal ion conditions. Herein, MnO2 nanosheet/DNAzyme (nanozyme) is fabricated as intracellular catalytic DNA circuit generator for high signal amplification, and its operation is reported for monitoring DNA base‐excision repair (BER) in living cells with improved performance. MnO2 nanosheet works as not only DNA nanocarrier but also as DNAzyme cofactor supplier. The nanozyme is constructed by adsorbing DNA probes on MnO2 nanosheets, facilitating cellular uptake of DNA. They are rapidly released in cellular environments by reducing MnO2 nanosheets to Mn2+ as DNAzyme cofactor. After repair enzyme activation, nanozymes are properly assembled with active folded conformation and hold sustained catalytic efficiency over many cycles. It offers at least 40‐fold amplified signals for the monitoring of apurinic/apyrimidinic endonuclease‐initiated and DNA glycosylase‐initiated BER pathways. Multiplex imaging can be allowed by integrating several sets of probes with per MnO2 nanosheet. The MnO2 nanozyme opens up exciting opportunities for imaging low‐abundance biomarkers and relevant biological pathways in living cells.
High Performance PbS Colloidal Quantum Dot Solar Cells by Employing Solution‐Processed CdS Thin Films from a Single‐Source Precursor as the Electron Transport Layer
Authors: Hu Long , Patterson Robert J. , Hu Yicong , Chen Weijian , Zhang Zhilong , Yuan Lin , Chen Zihan , Conibeer Gavin J. , Wang Gang , Huang Shujuan 
Published: October 2017

AbstractCdS thin films are a promising electron transport layer in PbS colloidal quantum dot (CQD) photovoltaic devices. Some traditional deposition techniques, such as chemical bath deposition and RF (radio frequency) magnetron sputtering, have been employed to fabricate CdS films and CdS/PbS CQD heterojunction photovoltaic devices. However, their power conversion efficiencies (PCEs) are moderate compared with ZnO/PbS and TiO2/PbS heterojunction CQD solar cells. Here, efficiencies have been improved substantially by employing solution‐processed CdS thin films from a single‐source precursor. The CdS film is deposited by a straightforward spin‐coating and annealing process, which is a simple, low‐cost, and high‐material‐usage fabrication process compared to chemical bath deposition and RF magnetron sputtering. The best CdS/PbS CQD heterojunction solar cell is fabricated using an optimized deposition and air‐annealing process achieved over 8% PCE, demonstrating the great potential of CdS thin films fabricated by the single‐source precursor for PbS CQDs solar cells.
Open Fluidics: A Cell Culture Flow System Developed Over Wettability Contrast‐Based Chips
Authors: Oliveira Nuno M. , Reis Rui L. , Mano João F. 
Published: October 2017

AbstractBiological tissues are recurrently exposed to several dynamic mechanical forces that influence cell behavior. On this work, the focus is on the shear stress forces induced by fluid flow. The study of flow‐induced effects on cells leads to important advances in cardiovascular, cancer, stem cell, and bone biology understanding. These studies are performed using cell culture flow (CCF) systems, mainly parallel plate flow chambers (PPFC), and microfluidic systems. Here, it is proposed an original CCF system based on the open fluidics concept. The system is developed using a planar superhydrophobic platform with hydrophilic paths. The paths work as channels to drive cell culture medium flows without using walls for liquid confinement. The liquid streams are controlled just based on the wettability contrast. To validate the concept, the effect of the shear stress stimulus in the osteogenic differentiation of C2C12 myoblast cells is studied. Combining bone morphogenic protein (specifically BMP‐2) stimulation with this mechanical stimulus, a synergistic effect is found on osteoblast differentiation. This effect is confirmed by the enhancement of alkaline phosphatase activity, a well‐known early marker of osteogenic differentiation. The suggested CCF system combines characteristics and advantages of both the PPFC and microfluidic systems.
Geometric Design of Scalable Forward Scatterers for Optimally Efficient Solar Transformers
Authors: Kim Hye‐Na , Vahidinia Sanaz , Holt Amanda L. , Sweeney Alison M. , Yang Shu 
Published: October 2017

AbstractIt will be ideal to deliver equal, optimally efficient “doses” of sunlight to all cells in a photobioreactor system, while simultaneously utilizing the entire solar resource. Backed by the numerical scattering simulation and optimization, here, the design, synthesis, and characterization of the synthetic iridocytes that recapitulated the salient forward‐scattering behavior of the Tridacnid clam system are reported, which presents the first geometric solution to allow narrow, precise forward redistribution of flux, utilizing the solar resource at the maximum quantum efficiency possible in living cells. The synthetic iridocytes are composed of silica nanoparticles in microspheres embedded in gelatin, both are low refractive index materials and inexpensive. They show wavelength selectivity, have little loss (the back‐scattering intensity is reduced to less than ≈0.01% of the forward‐scattered intensity), and narrow forward scattering cone similar to giant clams. Moreover, by comparing experiments and theoretical calculation, it is confirmed that the nonuniformity of the scatter sizes is a “feature not a bug” of the design, allowing for efficient, forward redistribution of solar flux in a micrometer‐scaled paradigm. This method is environmentally benign, inexpensive, and scalable to produce optical components that will find uses in efficiency‐limited solar conversion technologies, heat sinks, and biofuel production.
Flexible, High‐Wettability and Fire‐Resistant Separators Based on Hydroxyapatite Nanowires for Advanced Lithium‐Ion Batteries
Authors: Li Heng , Wu Dabei , Wu Jin , Dong Li‐Ying , Zhu Ying‐Jie , Hu Xianluo 
Published: October 2017

AbstractSeparators play a pivotal role in the electrochemical performance and safety of lithium‐ion batteries (LIBs). The commercial microporous polyolefin‐based separators often suffer from inferior electrolyte wettability, low thermal stability, and severe safety concerns. Herein, a novel kind of highly flexible and porous separator based on hydroxyapatite nanowires (HAP NWs) with excellent thermal stability, fire resistance, and superior electrolyte wettability is reported. A hierarchical cross‐linked network structure forms between HAP NWs and cellulose fibers (CFs) via hybridization, which endows the separator with high flexibility and robust mechanical strength. The high thermal stability of HAP NW networks enables the separator to preserve its structural integrity at temperatures as high as 700 °C, and the fire‐resistant property of HAP NWs ensures high safety of the battery. In particular, benefiting from its unique composition and highly porous structure, the as‐prepared HAP/CF separator exhibits near zero contact angle with the liquid electrolyte and high electrolyte uptake of 253%, indicating superior electrolyte wettability compared with the commercial polyolefin separator. The as‐prepared HAP/CF separator has unique advantages of superior electrolyte wettability, mechanical robustness, high thermal stability, and fire resistance, thus, is promising as a new kind of separator for advanced LIBs with enhanced performance and high safety.
Multiscale Humidity Visualization by Environmentally Sensitive Fluorescent Molecular Rotors
Authors: Cheng Yanhua , Wang Jianguo , Qiu Zijie , Zheng Xiaoyan , Leung Nelson L. C. , Lam Jacky W. Y. , Tang Ben Zhong 
Published: October 2017

AbstractBuilding humidity sensors possessing the features of diverse‐configuration compatibility, and capability of measurement of spatial and temporal humidity gradients is of great interest for highly integrated electronics and wearable monitoring systems. Herein, a visual sensing approach based on fluorescent imaging is presented, by assembling aggregation‐induced‐emission (AIE)‐active molecular rotors into a moisture‐captured network; the resulting AIE humidity sensors are compatible with diverse applications, having tunable geometries and desirable architectures. The invisible information of relative humidity (RH) is transformed into different fluorescence colors that enable direct observation by the naked eyes based on the twisted intramolecular charge‐transfer effect of the AIE‐active molecular rotors. The resulting AIE humidity sensors show excellent performance in terms of good sensitivity, precise quantitative measurement, high spatial–temporal resolution, and fast response/recovery time. Their multiscale applications, such as regional environmental RH detection, internal humidity mapping, and sensitive human‐body humidity sensing are demonstrated. The proposed humidity visualization strategy may provide a new insight to develop humidity sensors for various applications.
Synthesis of BSA‐Coated BiOI@Bi2S3 Semiconductor Heterojunction Nanoparticles and Their Applications for Radio/Photodynamic/Photothermal Synergistic Therapy of Tumor
Authors: Guo Zhao , Zhu Shuang , Yong Yuan , Zhang Xiao , Dong Xinghua , Du Jiangfeng , Xie Jiani , Wang Qing , Gu Zhanjun , Zhao Yuliang 
Published: October 2017

AbstractDeveloping an effective theranostic nanoplatform remains a great challenge for cancer diagnosis and treatment. Here, BiOI@Bi2S3@BSA (bovine serum albumin) semiconductor heterojunction nanoparticles (SHNPs) for triple‐combination radio/photodynamic/photothermal cancer therapy and multimodal computed tomography/photoacoustic (CT/PA) bioimaging are reported. On the one hand, SHNPs possess strong X‐ray attenuation capability since they contain high‐Z elements, and thus they are anticipated to be a very competent candidate as radio‐sensitizing materials for radiotherapy enhancement. On the other hand, as a semiconductor, the as‐prepared SHNPs offer an extra approach for reactive oxygen species generation based on electron–hole pair under the irradiation of X‐ray through the photodynamic therapy process. This X‐ray excited photodynamic therapy obviously has better penetration depth in bio‐tissue. What's more, the SHNPs also possess well photothermal conversion efficiency for photothermal therapy, because Bi2S3 is a thin band semiconductor with strong near‐infrared absorption that can cause local overheat. In vivo tumor ablation studies show that synergistic radio/photodynamic/photothermal therapy achieves more significant therapeutic effect than any single treatment. In addition, with the strong X‐ray attenuation and high near‐infrared absorption, the as‐obtained SHNPs can also be applied as a multimodal contrast agent in CT/PA imaging.
Monodispersed, Highly Interactive Facet (111)‐Oriented Pd Nanograins by ALD onto Free‐Standing and Flexible Electrospun Polymeric Nanofibrous Webs for Catalytic Application
Authors: Ranjith Kugalur Shanmugam , Celebioglu Asli , Eren Hamit , Biyikli Necmi , Uyar Tamer 
Published: October 2017

AbstractAn atomic layer deposition (ALD) of monodispersed palladium (Pd) nanograins (≈2 nm) onto electrospun polymeric nanofibers (NF) is presented. By ALD, monodispersed Pd nanograins with (111) exposed facets are decorated on the surface of the free‐standing flexible nanofibrous webs (NW). The Pd nanograin‐decorated free‐standing NW exhibit catalytic reduction of 4‐nitrophenol to 4‐aminophenol. Even under low loading capacity (≈20 µg mg−1), Pd nanograins manifest effective catalytic performance which can be referred to direct exposure of Pd single crystalline highly interactive (111) plains with high surface area on the NW. The Pd nanograins and the interactive sites along with the high surface area NW yield effective catalytic reduction of 4‐nitrophenol to 4‐aminophenol with the catalytic reduction rate of 0.0531 min−1. Pd nanograins display thermally tunable effective catalytic reduction properties with activation energy (Ea) of 1.705 J mol−1 on varying the reaction temperature from 12 to 42 °C. Moreover, Pd nanograin‐decorated NW are exhibited the effective reusable behavior with stable structural integrity even after repeated catalytic reactions. The approach of this study opens up synthesis and surface decoration of metal nanostructures onto NF through ALD with controlled size and facet orientation for designing reusable and free‐standing flexible catalytic nanofibrous materials.
Kraft Lignin as Electrode Material for Sustainable Electrochemical Energy Storage
Authors: Chaleawlert‐umpon Saowaluk , Berthold Thomas , Wang Xuewan , Antonietti Markus , Liedel Clemens 
Published: October 2017

AbstractElectrochemical energy storage using lignin as a renewable electrode material is a cheap and sustainable approach for future organic batteries. Previous reports mainly focus on lignosulfonates (LS) or composites with conductive polymer additives with inherent problems, such as still expensive monomers. Here, composite electrodes are used from more available Kraft lignin and sustainable conductive carbon. Charge storage is evaluated in terms of electrical double layer storage and redox reactions, aiming at a better understanding of desired lignin properties for electrochemical energy storage. Using unmodified, commercial lignin and high surface area conductive carbon, reasonable capacity of ≈80 mAh g−1 is achieved in samples in which a thin layer of lignin covers the interface of high surface area carbon. Non‐faradaic contribution to charge storage is as large as in comparable pure carbon electrodes, and redox reactions in lignin contribute to additional, faradaic charge storage, significantly enhancing capacity in these systems. Resulting electrodes are cheap, reliable, and stable.
Pursuing Polymer Dielectric Interfacial Effect in Organic Transistors for Photosensing Performance Optimization
Authors: Wu Xiaohan , Chu Yingli , Liu Rui , Katz Howard E. , Huang Jia 
Published: October 2017

AbstractPolymer dielectrics in organic field‐effect transistors (OFETs) are essential to provide the devices with overall flexibility, stretchability, and printability and simultaneously introduce charge interaction on the interface with organic semiconductors (OSCs). The interfacial effect between various polymer dielectrics and OSCs significantly and intricately influences device performance. However, understanding of this effect is limited because the interface is buried and the interfacial charge interaction is difficult to stimulate and characterize. Here, this challenge is overcome by utilizing illumination to stimulate the interfacial effect in various OFETs and to characterize the responses of the effect by measuring photoinduced changes of the OFETs performances. This systemic investigation reveals the mechanism of the intricate interfacial effect in detail, and mathematically explains how the photosensitive OFETs characteristics are determined by parameters including polar group of the polymer dielectric and the OSC side chain. By utilizing this mechanism, performance of organic electronics can be precisely controlled and optimized. OFETs with strong interfacial effect can also show a signal additivity caused by repeated light pulses, which is applicable for photostimulated synapse emulator. Therefore, this work enlightens a detailed understanding on the interface effect and provides novel strategies for optimizing OFET photosensory performances.
Implementation of a Novel Conference Series on Clinical Practice Variations Provides an Opportunity for Constructive Discussion of Faculty Practice Patterns: Do as We Say? … or Do as We Do?
Authors: Dorfsman Michele L. , Hart Danielle E. , Wolfson Allan B. 
Published: October 2017

AbstractBackgroundAlthough evidence‐based medicine (EBM) is routinely used to guide management in the emergency department, there is still considerable variation in clinical practice. Trainees may not fully appreciate the reasons for these clinical practice variations (CPVs) and may find it frustrating when they encounter them. We used areas of CPV among our faculty as the basis for resident educational sessions and assessed the perceived utility of these sessions.MethodsTopics were identified when residents noticed significant variability among the faculty in their management of particular clinical presentations. Sessions were conducted by facilitator‐led reviews of EBM guidelines, by faculty panel discussions of their management rationale where EBM guidelines are not available, or by pro–con debates. Residents were surveyed after the initial sessions to assess the utility of this series and changes in their understanding of CPV.ResultsThere was a 72% response rate. The percentage of residents who were frustrated with CPV decreased from 64% to 35%; the percentage who felt that the presence of CPV enhanced their learning increased from 19% to 48%. Sixty‐five percent felt that the educational series contributed to decreased frustration, 77% felt that the sessions helped them understand why CPV occurs, and 93% felt that they helped their overall learning.ConclusionExplicit discussion and exploration of CPV in an educational setting can provide multiple benefits. Trainees may gain a better understanding of why CPV occurs and of the rationale behind practice variations. Faculty may benefit from analyzing CPV to determine whether these truly represent the “art of medicine.”
Effect of sensory and motor connectivity on hand function in pediatric hemiplegia
Authors: Gupta Disha , Barachant Alexandre , Gordon Andrew M. , Ferre Claudio , Kuo Hsing‐Ching , Carmel Jason B. , Friel Kathleen M. 
Published: October 2017

ObjectiveWe tested the hypothesis that somatosensory system injury would more strongly affect movement than motor system injury in children with unilateral cerebral palsy (USCP). This hypothesis was based on how somatosensory and corticospinal circuits adapt to injury during development; whereas the motor system can maintain connections to the impaired hand from the uninjured hemisphere, this does not occur in the somatosensory system. As a corollary, cortical injury strongly impairs sensory function, so we hypothesized that cortical lesions would impair hand function more than subcortical lesions.MethodsTwenty‐four children with unilateral cerebral palsy had physiological and anatomical measures of the motor and somatosensory systems and lesion classification. Motor physiology was performed with transcranial magnetic stimulation and somatosensory physiology with vibration‐evoked electroencephalographic potentials. Tractography of the corticospinal tract and the medial lemniscus was performed with diffusion tensor imaging, and lesions were classified by magnetic resonance imaging. Anatomical and physiological results were correlated with measures of hand function using 2 independent statistical methods.ResultsChildren with disruptions in the somatosensory connectivity and cortical lesions had the most severe upper extremity impairments, particularly somatosensory function. Motor system connectivity was significantly correlated with bimanual function, but not unimanual function or somatosensory function.InterpretationBoth sensory and motor connectivity impact hand function in children with USCP. Somatosensory connectivity could be an important target for recovery of hand function in children with USCP. Ann Neurol 2017;82:766–780
Experimental Proof of the Bifunctional Mechanism for the Hydrogen Oxidation in Alkaline Media
Authors: Li Jingkun , Ghoshal Shraboni , Bates Michael K. , Miller Todd E , Davies Veronica , Stavitski Eli , Attenkofer Klaus , Mukerjee Sanjeev , Ma Zi‐Feng , Jia Qingying 
Published: October 2017

AbstractRealization of the hydrogen economy relies on effective hydrogen production, storage, and utilization. The slow kinetics of hydrogen evolution and oxidation reaction (HER/HOR) in alkaline media limits many practical applications involving hydrogen generation and utilization, and how to overcome this fundamental limitation remains debatable. Here we present a kinetic study of the HOR on representative catalytic systems in alkaline media. Electrochemical measurements show that the HOR rate of Pt‐Ru/C and Ru/C systems is decoupled to their hydrogen binding energy (HBE), challenging the current prevailing HBE mechanism. The alternative bifunctional mechanism is verified by combined electrochemical and in situ spectroscopic data, which provide convincing evidence for the presence of hydroxy groups on surface Ru sites in the HOR potential region and its key role in promoting the rate‐determining Volmer step. The conclusion presents important references for design and selection of HOR catalysts.
Programmierbare transiente Thermogele vermittelt durch eine pH‐ und Redox‐regulierte supramolekulare Polymerisation
Authors: Spitzer Daniel , Rodrigues Leona Lucas , Straßburger David , Mezger Markus , Besenius Pol 
Published: October 2017

AbstractWir stellen eine durch mehrfache Stimuli ansprechbare transiente supramolekulare Polymerisation von β‐Faltblatt‐kodierten dendritischen Peptidmonomeren in Wasser vor. Die Glutaminsäure‐ und Methionin‐tragenden Amphiphile gehen eine durch Glucose‐Oxidase katalysierte und Glucose‐getriebene transiente Hydrogelierung ein. Diese basiert auf einem Zusammenspiel eines pH‐ und oxidativen Stimulus, der durch die Produktion reaktiver Sauerstoffspezies (ROS) gefördert wird. Mit Veränderung der Enzym‐ und Glucosekonzentration wird eine Feineinstellung der Assemblierungs‐ sowie Disassemblierungsgeschwindigkeit vorgenommen, wodurch die Steifigkeit und Stabilität des transienten Hydrogels bestimmt wird. Die Verwendung von Triethylenglycolketten führt zu thermoresponsiven Eigenschaften der Materialien. Weiterhin zeigen wir, dass Reparaturenzyme den oxidativen Schaden in den Methionin‐basierten Thioetherseitenketten beheben können. Da reaktive Sauerstoffspezies eine wichtige Rolle in Signaltransduktionskaskaden spielen, bietet unsere Strategie großes Potential zur Anwendung dieser dynamischen Biomaterialien in redoxaktiven Mikroumgebungen.
Reduction of a Cerium(III) Siloxide Complex To Afford a Quadruple‐Decker Arene‐Bridged Cerium(II) Sandwich
Authors: Kelly Rory P. , Maron Laurent , Scopelliti Rosario , Mazzanti Marinella 
Published: October 2017

AbstractOrganometallic multi‐decker sandwich complexes containing f‐elements remain rare, despite their attractive magnetic and electronic properties. The reduction of the CeIII siloxide complex, [KCeL4] (1; L=OSi(OtBu)3), with excess potassium in a THF/toluene mixture afforded a quadruple‐decker arene‐bridged complex, [K(2.2.2‐crypt)]2[{(KL3Ce)(μ‐η6:η6‐C7H8)}2Ce] (3). The structure of 3 features a [Ce(C7H8)2] sandwich capped by [KL3Ce] moieties with a linear arrangement of the Ce ions. Structural parameters, UV/Vis/NIR data, and DFT studies indicate the presence of CeII ions involved in δ bonding between the Ce cations and toluene dianions. Complex 3 is a rare lanthanide multi‐decker complex and the first containing non‐classical divalent lanthanide ions. Moreover, oxidation of 1 by AgOTf (OTf=O3SCF3) yielded the CeIV complex, [CeL4] (2), showing that siloxide ligands can stabilize Ce in three oxidation states.