Saturday, August 02, 2014

pH-responsive polymer–drug conjugates as multifunctional micelles for cancer-drug delivery

We developed a novel linear pH-sensitive conjugate methoxy poly(ethylene glycol)-4 β -aminopodophyllotoxin (mPEG-NPOD-I) by a covalently linked 4 β -aminopodophyllotoxin (NPOD) and PEG via imine bond, which was amphiphilic and self-assembled to micelles in an aqueous solution. The mPEG-NPOD-I micelles simultaneously served as an anticancer drug conjugate and as drug carriers. As a drug conjugate, mPEG-NPOD-I showed a significantly faster NPOD release at a mildly acidic pH of 5.0 and 4.0 than a physiological pH of 7.4. Notably, it was confirmed that this drug conjugate could efficiently deliver NPOD to the nuclei of the tumor cells and led to much more cytotoxic effects to A549, Hela, and HepG2 cancer cells than the parent NPOD. The half maximal inhibitory concentration (IC 50 ) of mPEG-NPOD-I was about one order magnitude lower than that of the NPOD. In vivo , mPEG-NPOD-I reduced the size of the tumors significantly, and the biodistribution studies indica...

Yang Kang, Wei Ha, Ying-Qian Liu, Yuan Ma, Min-Min Fan, Li-Sheng Ding, Sheng Zhang and Bang-Jing Li

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Four-fold Raman enhancement of 2D band in twisted bilayer graphene: evidence for a doubly degenerate Dirac band and quantum interference

We report the observation of a strong 2D band Raman in twisted bilayer graphene (tBLG) with large rotation angles under 638 nm and 532 nm visible laser excitations. The 2D band Raman intensity increased four-fold as opposed to the two-fold increase observed in single-layer graphene. The same tBLG samples also exhibited rotation-dependent G-line resonances and folded phonons under 364 nm UV laser excitation. We attribute this 2D band Raman enhancement to the constructive interference between two double-resonance Raman pathways, which were enabled by a nearly degenerate Dirac band in the tBLG Moiré superlattices.

Yanan Wang, Zhihua Su, Wei Wu, Shu Nie, Xinghua Lu, Haiyan Wang, Kevin McCarty, Shin-shem Pei, Francisco Robles-Hernandez, Viktor G Hadjiev and Jiming Bao

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Selective growth and ordering of SiGe nanowires for band gap engineering

Selective growth and self-organization of silicon-germanium (SiGe) nanowires (NWs) on focused ion beam (FIB) patterned Si(111) substrates is reported. In its first step, the process involves the selective synthesis of Au catalysts in ##IMG## [http://ift.tt/1AxYuaB] {${\rm Si}{{{\rm O}}_{2}}$} -free areas; its second step involves the preferential nucleation and growth of SiGe NWs on the catalysts. The selective synthesis process is based on a simple, room-temperature reduction of gold salts ( ##IMG## [http://ift.tt/1xyrASS] {${\rm A}{{{\rm u}}^{3+}}{\rm Cl}_{4}^{-}$} ) in aqueous solution, which provides well-organized Au catalysts. By optimizing the reduction process, we are able to generate a bidimensional regular array of Au catalysts with self-limited sizes positioned in ##IMG## [http://ej.iop.org/...] {${\rm Si}{{{\rm O}}_{2}}$}

A Benkouider, A Ronda, A Gouyé, C Herrier, L Favre, D J Lockwood, N L Rowell, A Delobbe, P Sudraud and I Berbezier

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Majority logic gate for 3D magnetic computing

For decades now, microelectronic circuits have been exclusively built from transistors. An alternative way is to use nano-scaled magnets for the realization of digital circuits. This technology, known as nanomagnetic logic (NML), may offer significant improvements in terms of power consumption and integration densities. Further advantages of NML are: non-volatility, radiation hardness, and operation at room temperature. Recent research focuses on the three-dimensional (3D) integration of nanomagnets. Here we show, for the first time, a 3D programmable magnetic logic gate. Its computing operation is based on physically field-interacting nanometer-scaled magnets arranged in a 3D manner. The magnets possess a bistable magnetization state representing the Boolean logic states ‘0’ and ‘1.’ Magneto-optical and magnetic force microscopy measurements prove the correct operation of the gate over many computing cycles. Furthermore, micromagnetic simulations confirm the correct functionalit...

Irina Eichwald, Stephan Breitkreutz, Grazvydas Ziemys, György Csaba, Wolfgang Porod and Markus Becherer

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Friday, August 01, 2014

Synthesis, Characterization, and Computation of Catalysts at the Center for Atomic-Level Catalyst Design

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The Journal of Physical Chemistry C

DOI: 10.1021/jp502556u




James J. Spivey, Katla Sai Krishna, Challa S.S.R. Kumar, Kerry M. Dooley, John C. Flake, Louis H. Haber, Ye Xu, Michael J. Janik, Susan B. Sinnott, Yu-Ting Cheng, Tao Liang, David S. Sholl, Thomas A. Manz, Ulrike Diebold, Gareth S. Parkinson, David A. Bruce and Petra de Jongh

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Photoswitching Azobenzene Derivatives in Single Molecule Junctions: A Theoretical Insight into the I/V Characteristics

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The Journal of Physical Chemistry C

DOI: 10.1021/jp504582a




Silvio Osella, Paolo Samorì and Jérôme Cornil

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Synthesis Process Controlled of Semimagnetic Bi2–xMnxS3 Nanocrystals in a Host Glass Matrix

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The Journal of Physical Chemistry C

DOI: 10.1021/jp5046657




R. S. Silva, J. T. T. Silva, V. R. Rocha, N. F. Cano, A. C. A. Silva and N. O. Dantas

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Kinetic Analysis of the Catalytic Reduction of 4-Nitrophenol by Metallic Nanoparticles

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The Journal of Physical Chemistry C

DOI: 10.1021/jp5060606




Sasa Gu, Stefanie Wunder, Yan Lu, Matthias Ballauff, Robert Fenger, Klaus Rademann, Baptiste Jaquet and Alessio Zaccone

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Three-Dimensional Bicomponent Supramolecular Nanoporous Self-Assembly on a Hybrid All-Carbon Atomically Flat and Transparent Platform

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Nano Letters

DOI: 10.1021/nl501452s




Juan Li, Sarah Wieghold, Murat Anil Öner, Patrick Simon, Moritz V. Hauf, Emanuela Margapoti, Jose A. Garrido, Friedrich Esch, Carlos-Andres Palma and Johannes V. Barth

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Maximizing the Electromagnetic and Chemical Resonances of Surface-Enhanced Raman Scattering for Nucleic Acids

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ACS Nano

DOI: 10.1021/nn5028664




Lindsay M. Freeman, Lin Pang and Yeshaiahu Fainman

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Impact Electrochemistry: Measuring Individual Nanoparticles

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ACS Nano

DOI: 10.1021/nn503831r




Martin Pumera

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Solution Processing of GaAs Thin Films for Photovoltaic Applications

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Chemistry of Materials

DOI: 10.1021/cm501280e




Sanjayan Sathasivam, Ranga Rao Arnepalli, Bhaskar Kumar, Kaushal K. Singh, Robert J. Visser, Christopher S. Blackman and Claire J. Carmalt

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Substitutional Doping Widens Silicene Gap

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The Journal of Physical Chemistry C

DOI: 10.1021/jp5060809




Alejandro Lopez-Bezanilla

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Kinetic Investigation on the Confined Etching System of n-Type Gallium Arsenide by Scanning Electrochemical Microscopy

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The Journal of Physical Chemistry C

DOI: 10.1021/jp5056446




Jie Zhang, Jingchun Jia, Lianhuan Han, Ye Yuan, Zhong-Qun Tian, Zhao-Wu Tian and Dongping Zhan

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Internal Stress-Induced Orthorhombic Phase in 5-Fold-Twinned Noble Metal Nanowires

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The Journal of Physical Chemistry C

DOI: 10.1021/jp505334x




Ya Zhou and Kristen A. Fichthorn

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Giant Rectification Ratios of Azulene-like Dipole Molecular Junctions Induced by Chemical Doping in Armchair-Edged Graphene Nanoribbon Electrodes

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The Journal of Physical Chemistry C

DOI: 10.1021/jp504448n




Yang Song, Zhen Xie, Yong Ma, Zong-liang Li and Chuan-Kui Wang

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Semiconductor-like Sensitivity in Metallic Ultrathin Gold Nanowire-Based Sensors

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The Journal of Physical Chemistry C

DOI: 10.1021/jp5042052




Ahin Roy, Tribhuwan Pandey, N. Ravishankar and Abhishek K. Singh

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Highly Controllable and Stable Quantized Conductance and Resistive Switching Mechanism in Single-Crystal TiO2 Resistive Memory on Silicon

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Nano Letters

DOI: 10.1021/nl501249q




Chengqing Hu, Martin D. McDaniel, Agham Posadas, Alexander A. Demkov, John G. Ekerdt and Edward T. Yu

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Doping Poly(3-hexylthiophene) Nanowires with Selenophene Increases the Performance of Polymer-Nanowire Solar Cells

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Chemistry of Materials

DOI: 10.1021/cm501985d




Han Yan, Jon Hollinger, Colin R. Bridges, George R. McKeown, Tamara Al-Faouri and Dwight S. Seferos

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Dye-Sensitized MoS2 Photodetector with Enhanced Spectral Photoresponse

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ACS Nano

DOI: 10.1021/nn502715h




Seong Hun Yu, Youngbin Lee, Sung Kyu Jang, Jinyeong Kang, Jiwon Jeon, Changgu Lee, Jun Young Lee, Hyungjun Kim, Euyheon Hwang, Sungjoo Lee and Jeong Ho Cho

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Chemically Integrated Two-Dimensional Hybrid Zinc Manganate/Graphene Nanosheets with Enhanced Lithium Storage Capability

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ACS Nano

DOI: 10.1021/nn5041203




Pan Xiong, Borui Liu, Vincent Teran, Yu Zhao, Lele Peng, Xin Wang and Guihua Yu

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