bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Theranostic Nanoplatform Based on Pd@Pt‐PEG‐Ce6 for Enhanced Photodynamic Therapy by Modulating Tumor Hypoxia Microenvironment
Authors: Wei Jingping , Li Jingchao , Sun Duo , Li Qi , Ma Jinyuan , Chen Xiaolan , Zhu Xuan , Zheng Nanfeng 
Published: February 2018

AbstractPhotodynamic therapy (PDT), which utilizes reactive oxygen species to kill cancer cells, has found wide applications in cancer treatment. However, the hypoxic nature of most solid tumors can severely restrict the efficiency of PDT. Meanwhile, the hydrophobicity and limited tumor selectivity of some photosensitizers also reduce their PDT efficacy. Herein, a photosensitizer‐Pd@Pt nanosystem (Pd@Pt‐PEG‐Ce6) is designed for highly efficient PDT by overcoming these limitations. In the nanofabrication, Pd@Pt nanoplates, exhibiting catalase‐like activity to decompose H2O2 to generate oxygen, are first modified with bifunctional PEG (SH‐PEG‐NH2). Then the Pd@Pt‐PEG is further covalently conjugated with the photosensitizer chlorin e6 (Ce6) to get Pd@Pt‐PEG‐Ce6 nanocomposite. The Pd@Pt‐PEG‐Ce6 exhibits good biocompatibility, long blood circulation half‐life, efficient tumor accumulation, and outstanding imaging properties. Both in vitro and in vivo experimental results clearly indicate that Pd@Pt‐PEG‐Ce6 effectively delivers photosensitizers to cancer cells/tumor sites and triggers the decomposition of endogenous H2O2 to produce oxygen, resulting in a remarkably enhanced PDT efficacy. Moreover, the moderate photothermal effect of Pd@Pt nanoplates also strengthen the PDT of Pd@Pt‐PEG‐Ce6. Therefore, by integrating the merits of high tumor‐specific accumulation, hypoxia modulation function, and mild photothermal effect into a single nanoagent, Pd@Pt‐PEG‐Ce6 readily acts as an ideal nanotherapeutic platform for enhanced cancer PDT.
Rational Design of Nanostructured Functional Interlayer/Separator for Advanced Li–S Batteries
Authors: Jeong Yo Chan , Kim Jae Ho , Nam Seunghoon , Park Chong Rae , Yang Seung Jae 
Published: February 2018

AbstractThe lithium–sulfur (Li–S) battery is considered as a promising future energy storage device owing to its high theoretical energy density, low cost of the raw active material (sulfur), and its environmental friendliness. On the other hand, there are still challenging issues for the practical applications of Li–S batteries, including low sulfur utilization, poor cyclability, and rate capability. Although considerable efforts are made to overcome the current obstacles in Li–S batteries, one is still far from meeting the requirements for the commercialization of Li–S batteries. This review outlines the recent progress in Li–S batteries based on novel configurations, such as incorporating functional interlayers/separators beyond the approach for preparing novel cathodes, and discusses the role of the configuration in Li–S batteries. The functions of the newly introduced functional interlayer/separator are highlighted to address the problems of Li–S batteries. From classification of the functions, the perspectives and outlook are presented to rationally design a novel functional interlayer/separator for high‐performance Li–S batteries.
Hollow Structural Transition Metal Oxide for Advanced Supercapacitors
Authors: Wei Jilei , Li Xinran , Xue Huaiguo , Shao Jinying , Zhu Rongmei , Pang Huan 
Published: February 2018

AbstractElectrochemical capacitors (supercapacitors, SCs), have been deemed to be one of the most promising powerful electrochemical energy storage devices, owing to that SCs have long cycle lives, high power densities, and fast recharge capabilities. Transition metal oxide is one of the most promising electrode materials in the application of SCs, but the poor active surface areas limit their electrochemical performances. Particularly, hollow structures can enhance their active surface areas and porosity for better transportation. In this review, the development regarding hollow structures of the metal oxide, metal oxide complex, and carbon–metal oxide complex is discussed. Furthermore, performances of these materials applied in SCs are tested in various systems, and their electrochemical performances are introduced and compared. The disadvantages of SCs based on hollow metal oxide materials are also discussed, and the various solutions are provided.
Viologen‐Hypercrosslinked Ionic Porous Polymer Films as Active Layers for Electronic and Energy Storage Devices
Authors: Wang Luxin , Ding Junjie , Sun Sai , Zhang Bin , Tian Xiangyu , Zhu Jinhui , Song Sannian , Liu Bo , Zhuang Xiaodong , Chen Yu 
Published: February 2018

AbstractOver the past decades, numerous scientists have focused on designing complicated monomers, developing new synthesis protocols, and optimizing chemical structures for realizing high‐performance organic or polymer electronics and energy storage devices. However, much less attention has been paid to ionic‐ and radical‐rich porous organic films, which are essential components of aforementioned devices. In this study, an air‐stable, large‐area, free‐standing, and viologen‐linked ionic porous polymer (denoted as IPP‐V) film is developed in situ through electrochemical polymerization. This film is applied to a device by sandwiching it between indium tin oxide (ITO) and Au (i.e., ITO/IPP‐V/Au); the device exhibits a memristive behavior with an ON–OFF current ratio of ≈2. After the IPP‐V film is subjected to thermal pyrolysis at 500 °C, the as‐produced film (denoted as IPP‐V‐500) acts as an active material for an in‐plane micro‐supercapacitor and exhibits a high volumetric capacitance level of up to 4.44 F cm−3. This work not only offers a new and convenient strategy toward large‐area ionic porous polymer films for memristor, but also provides a new porous polymer derived carbon film for energy storage.
An Effective Strategy toward High‐Efficiency Fluorescent OLEDs by Radiative Coupling of Spatially Separated Electron–Hole Pairs
Authors: Li Binbin , Gan Lin , Cai Xinyi , Li Xiang‐Long , Wang Zhiheng , Gao Kuo , Chen Dongcheng , Cao Yong , Su Shi‐Jian 
Published: February 2018

AbstractAn effective strategy toward low‐driving voltage and high‐efficiency fluorescent organic light‐emitting diodes (OLEDs) by long‐range radiative coupling of spatially separated electron–hole pairs is proposed. Charge transfer excited states between p‐type hole‐transport layer and n‐type electron‐transport layer can be achieved although they are separated by an interlayer, giving significantly reduced efficiency roll‐off and higher luminance compared with the devices based on interface exciplex. Remarkable external quantum efficiency near 15% is also achieved by employing conventional red fluorescent dyes doped into the hole‐transport layer adjacent to the interlayer due to the avoidance of the direct carrier trapping and thus the generation of unwanted nonradiative triplet excitons. Different from the conventional devices with a host–guest structure for both exciton generation and energy releasing, such unique device concept provides a bright avenue toward structure‐simplified and high‐performance fluorescent OLEDs, where the long‐range coupled radiative excitons and the following energy releasing are separated in their own channels.
Graphene–Perovskite Schottky Barrier Solar Cells
Authors: Song Yi , Osherov Anna , Bulović Vladimir , Kong Jing 
Published: February 2018

AbstractPerovskite solar cells have attained incredible power conversion efficiencies but it is still unclear whether photogenerated carriers are free or excitonic in nature. Originally, it is believed that they are exciton‐based devices, similar to organic or dye‐sensitized solar cells. However, the emergence of efficient planar devices as well as measurements of exciton binding energy in the range of 10–100 meV suggest that they may be free carrier‐based. In this work, the free carrier model is confirmed by building graphene/perovskite Schottky barrier solar cells, analogous to conventional metal/semiconductor Schottky barrier solar cells. To address the challenges of building such devices, solution‐processing techniques are extensively investigated for depositing perovskite films directly onto graphene in order to obtain an intimate contact between the graphene and perovskite. Interestingly, these graphene/perovskite Schottky barrier devices have reasonably good efficiency—up to 10.6%—and short circuit current densities only slightly lower than control devices. Furthermore, devices with neither a hole transport layer nor an electron transport layers have power conversion efficiencies of up to 6%. These results provide convincing evidence supporting the free carrier model for methylammonium lead iodide perovskites and offer insights on potential alternative designs for perovskite solar cells.
A low‐cost ultrasound model for simulation of paediatric distal forearm fractures
Authors: Snelling Peter James 
Published: February 2018

AbstractBackgroundForearm injuries are a common presentation to the emergency department. Point‐of‐care ultrasound has been demonstrated to be an accurate and well‐tolerated tool in the diagnosis of non‐angulated paediatric distal forearm fractures. Ultrasound model simulation is a practical alternative for ultrasound education.AimsTo describe the construction and validation of a low‐cost ultrasound model for the simulation of non‐angulated paediatric buckle and greenstick distal forearm fractures, for the educational instruction of healthcare providers.Materials & MethodsThe materials for the basic paediatric fracture model include turkey or chicken bones soaked in white vinegar to make them pliable, food‐grade gelatine and plastic containers. The fidelity can be improved by using synthetic gelatine set in a cylindrical mould, which can be placed within a manikin forearm.ResultsThe models were validated by five paediatric emergency nurse practitioners and five paediatric emergency physicians. All participants were able to correctly identify the fracture types. All participants rated the models highly for both realism and educational value, with a preference for the turkey bone model as a better representation of buckle fractures.DiscussionThe ultrasound model described in this article can be made from low‐cost materials that can be easily sourced, which facilitates the identification of the different paediatric fracture subtypes, with the additional advantage of not causing discomfort to a child. A limitation of this model includes its inability to simulate the radiolucent epiphysis and represent Salter‐Harris fracture subtypes.ConclusionThis low‐cost, high‐fidelity ultrasound model presents both an accurate and practical educational model for training healthcare providers, with a preference towards the turkey bone model.
Magnetic Mesoporous Silica Nanoparticles Cloaked by Red Blood Cell Membranes: Applications in Cancer Therapy
Authors: Xuan Mingjun , Shao Jingxin , Zhao Jie , Li Qi , Dai Luru , Li Junbai 
Published: February 2018

AbstractTargeted drug delivery is an emerging technological strategy that enables nanoparticle systems to be responsive for tumor therapy. Magnetic mesoporous silica nanoparticles (MMSNs) were cloaked with red blood cell membrane (RBC). This integrates long circulation, photosensitizer delivery, and magnetic targeting for cancer therapy. In vivo experiments demonstrate that RBC@MMSNs can avoid immune clearance and achieve magnetic field (MF)‐induced high accumulation in a tumor. When light irradiation is applied, singlet oxygen rapidly generates from hypocrellin B (HB)‐loaded RBC@MMSN and leads to the necrosis of tumor tissue. Such a RBC‐cloaked magnetic nanocarrier effectively integrates immunological adjuvant, photosensitizer delivery, MF‐assisted targeting photodynamic therapy, which provides an innovative strategy for cancer therapy.
Palladium‐Catalyzed Decarbonylative Trifluoromethylation of Acid Fluorides
Authors: Keaveney Sinead T. , Schoenebeck Franziska 
Published: February 2018

AbstractWhile acid fluorides can readily be made from widely available or biomass‐feedstock‐derived carboxylic acids, their use as functional groups in metal‐catalyzed cross‐coupling reactions is rare. This report presents the first demonstration of Pd‐catalyzed decarbonylative functionalization of acid fluorides to yield trifluoromethyl arenes (ArCF3). The strategy relies on a Pd/Xantphos catalytic system and the supply of fluoride for transmetalation through intramolecular redistribution to the the Pd center. This strategy eliminated the need for exogenous and detrimental fluoride additives and allows Xantphos to be used in catalytic trifluoromethylations for the first time. Our experimental and computational mechanistic data support a sequence in which transmetalation by R3SiCF3 occurs prior to decarbonylation.
Peptide‐Guided Assembly of Repeat Protein Fragments
Authors: Michel Erich , Plückthun Andreas , Zerbe Oliver 
Published: February 2018

AbstractHerein, we present the peptide‐guided assembly of complementary fragments of designed armadillo repeat proteins (dArmRPs) to create proteins that bind peptides not only with high affinity but also with good selectivity. We recently demonstrated that complementary N‐ and C‐terminal fragments of dArmRPs form high‐affinity complexes that resemble the structure of the full‐length protein, and that these complexes bind their target peptides. We now demonstrate that dArmRPs can be split such that the fragments assemble only in the presence of a templating peptide, and that fragment mixtures enrich the combination with the highest affinity for this peptide. The enriched fragment combination discriminates single amino acid variations in the target peptide with high specificity. Our results suggest novel opportunities for the generation of new peptide binders by selection from dArmRP fragment mixtures.
Synthesis of (−)‐Hebelophyllene E: An Entry to Geminal Dimethyl‐Cyclobutanes by [2+2] Cycloaddition of Alkenes and Allenoates
Authors: Wahl Johannes M. , Conner Michael L. , Brown M. Kevin 
Published: February 2018

AbstractThe first synthesis of hebelophyllene E is presented, along with assignment of its previously unknown relative configuration through synthesis of epi‐ent‐hebelophyllene E. Development of a catalytic enantioselective [2+2] cycloaddition of alkenes and allenoates provides access to the required chiral geminal dimethylcyclobutanes. Key to its success is the identification of a novel oxazaborolidine catalyst which promotes the cycloaddition in high enantioselectivities with good functional‐group tolerance (9 examples, up to 97:3 e.r.). Thus, a late‐stage cycloaddition using a fully functionalized alkene, followed by a diastereoselective reduction allows a concise entry to this class of natural products.
A Ligand System for the Flexible Functionalization of Quantum Dots via Click Chemistry
Authors: Chen Yue , Cordero Jose M. , Wang Hua , Franke Daniel , Achorn Odin B. , Freyria Francesca S. , Coropceanu Igor , Wei He , Chen Ou , Mooney David J. , Bawendi Moungi G. 
Published: February 2018

AbstractWe present a novel ligand, 5‐norbornene‐2‐nonanoic acid, which can be directly added during established quantum dot (QD) syntheses in organic solvents to generate “clickable” QDs at a few hundred nmol scale. This ligand has a carboxyl group at one terminus to bind to the surface of QDs and a norbornene group at the opposite end that enables straightforward phase transfer of QDs into aqueous solutions via efficient norbornene/tetrazine click chemistry. Our ligand system removes the traditional ligand‐exchange step and can produce water‐soluble QDs with a high quantum yield and a small hydrodynamic diameter of approximately 12 nm at an order of magnitude higher scale than previous methods. We demonstrate the effectiveness of our approach by incubating azido‐functionalized CdSe/CdS QDs with 4T1 cancer cells that are metabolically labeled with a dibenzocyclooctyne‐bearing unnatural sugar. The QDs exhibit high targeting efficiency and minimal nonspecific binding.
Utility of silver‐coated fabrics as electrodes in electrotherapy applications
Authors: Ali Azam , Baheti Vijay , Militky Jiri , Khan Zaman 
Published: February 2018

ABSTRACTThe present study deals with the deposition of silver particles onto knitted fabrics for possible applications in electrotherapy. The performance of silver‐coated fabrics was evaluated based on number of properties such as electrical conductivity, physiological comfort, antibacterial, and durability. Furthermore, the conductive fabrics were subjected to various repeated extensions and change in electrical resistivity was examined to simulate the performance of electrodes under various movements of human body. With increase in extension till 80%, very small change in volume electrical resistance was observed and after 90% extension, the electrical resistance was found to increase significantly. The volume resistance was found to remain constant for repeated extensions of over 100 cycles and also there was insignificant change in electrical resistivity when constant current was applied over prolonged time. The utility of silver‐coated fabrics can be expected as flexible textile electrodes in transcutaneous electrical nerve stimulation electrotherapy applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46357.
Fast swelling behaviors of thermosensitive poly(N‐isopropylacrylamide‐co‐methacryloxyethyltrimethyl ammonium chloride)/Na2WO4 cationic composite hydrogels
Authors: Xiao Zhixin , Tan Yun , Ma Jianjun , Wang Di , Yu Lina , Yue Fan , Xu Shimei , Huang Jianbin 
Published: February 2018

ABSTRACTA facile method was explored to synthesize thermosensitive poly[N‐isopropylacrylamide (NIPAM)‐co‐methacryloxyethyltrimethyl ammonium chloride (DMC)]/Na2WO4 cationic hydrogels via copolymerization of NIPAM and DMC in the presence of Na2WO4. Na2WO4 acted as both a physical crosslinking agent and a porogen precursor. The hydrogels were characterized by Fourier transform infrared spectroscopy, energy dispersive X‐ray, thermogravimetry, environmental scanning electron microscopy, and transmission electron microscopy. Effects of various salt solutions, pH solutions on swelling were investigated. Thermosensitivity of the hydrogels were also investigated in various polar solvents at different temperatures. The resultant hydrogel showed a fast swelling rate and good salt tolerance. The hydrogels reached the swelling equilibrium within 10 min. Moreover, the swelling ratio of the hydrogels increased with the increase of the polarity of the solvent. In the water, the swelling ratio decreased with the increasing of temperature, but remained at a high level even at 80 °C since the pore structure weaken the lower critical solution temperature effect of PNIPAM. The swelling ratio increased instead in low polar solvent, while it became negligible in nonpolar solvent with the increasing of temperature. The whole swelling kinetics was fit for Schott's pseudo‐second order model. The hydrogels have a great potential as catalysts and smart materials. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46375.
Study on spinnability of polyacrylonitrile solution based on dynamics simulation of dry‐jet wet spinning
Authors: Wang Jianning , Wang Tao , Xu Jing , Yu Jinchao , Zhang Yumei , Wang Huaping 
Published: February 2018

ABSTRACTSpinnability of polyacrylonitrile (PAN) solution was studied based on the spinning dynamics simulation and dry‐jet wet spinning experiments. The spinnability phenomenon was observed from the extruding and extending spinning experiments. The suitable conditions of normal extruding and extending of the PAN solution were obtained and the critical spinnability conditions were simulated. The experimental and simulation results showed that pressure drop through the spinneret was similar, while the temperature, velocity, and velocity gradient through the spinneret of PAN solution changed dramatically. It suggests that pressure drop can be chosen as one of the spinnability criterion for solution extruding and filaments forming during dry‐jet wet spinning. Furthermore, the effect of spinneret parameters and spinning conditions on spinnability was simulated. It shows that spinneret entrance angle, outlet channel length and width have impacts on the pressure drop and the die swell ratio, which suggests the spinneret design can be optimized to regulate the spinnability according to the simulation results. It is also found that some bad situations of spinnability such as sticking phenomenon can be avoided by decreasing spinning temperature or increasing mass flow rate to increase the pressure drop at a certain level under the premise of extruding smoothly. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46377.
2:2 Complexes from Diphenylpyridiniums and Cucurbit[8]uril: Encapsulation‐Promoted Dimerization of Electrostatically Repulsing Pyridiniums
Authors: Yang Bo , Yu Shang‐Bo , Wang Hui , Zhang Dan‐Wei , Li Zhan‐Ting 
Published: February 2018

AbstractRigid linear compounds G1 and G2, which contained two 4‐phenylpyridinium (PhPy+) units, have been prepared to investigate their binding with cucurbit[8]uril (CB[8]). X‐ray crystallographic structures revealed that in the solid state both compounds were included by CB[8], through antiparallel stacking, to form 2:2 quaternary complexes (G1)2@(CB[8])2 and (G2)2@(CB[8])2. For the former complex, CB[8] entrapped G1 by holding two heterodimers of its Py+ and benzyl units, which were at opposite ends of the backbone. In contrast, for the first time, the second complex disclosed parallel stacking of two cationic Py+ units of G2 in the cavity of CB[8] in the solid state, despite the generation of important electrostatic repulsion. Isothermal titrations in water afforded high apparent association constants of 4.36×106 and 6.43×106 m−1 for 1:1 complexes G1@CB[8] and G2@CB[8], respectively, and 1H NMR spectroscopy experiments in D2O confirmed a similar stacking pattern to that observed in the solid state. A previous study and crystal structures of the 2:1 complexes formed between three new controls, G3–5, and CB[8] did not display such unusual stacking of the cationic Py+ unit; this may be attributed to the multivalency of the two CB[8] encapsulation interactions.
Artificial Composite Anode Comprising High‐Capacity Silicon and Carbonaceous Nanostructures for Long Cycle Life Lithium‐Ion Batteries
Authors: Breitung Ben , Schneider Artur , Chakravadhanula Venkata Sai Kiran , Suchomski Christian , Janek Jürgen , Sommer Heino , Brezesinski Torsten 
Published: February 2018

AbstractThe use of functional nanomaterials is a common strategy to improve the mechanical and electrochemical properties of silicon anodes for secondary lithium‐ion cells. Here, we report the preparation of a structurally stable composite material with a unique morphology comprising small‐size silicon particles and especially branched carbonaceous nanofibers and the analysis of its cycling performance by galvanostatic measurements. This two‐phase composite was obtained from pyrolysis of blended silicon/cyanamide powders. The conversion of cyanamide to turbostratic carbon, rather than graphitic carbon nitride, was unexpected and appears to be catalyzed by accidental iron nanoparticles. Although the carbon content after pyrolysis was only about 7 %, half‐cells using electrodes containing the silicon/carbon composite outperformed other silicon‐based anode materials tested herein in terms of cyclability. After 300 cycles, they delivered two times higher capacity (>1.7 A h gsilicon−1 at C/10 and >0.5 A h gsilicon−1 at 1C in the 600–30 mV range when operated in constant current mode) than cells of similar loading with pristine silicon particles. The average fade rate per cycle was around 0.1 % between the 10th and 300th cycles, which is notable considering that the electrode structure and composition have not yet been optimized for battery applications.