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101.
Synthesis of Nucleobase‐Functionalized Carbon Nanotubes and Their Hybridization with Single‐Stranded DNA 下载免费PDF全文
Prof. Jih Ru Hwu Mohit Kapoor Rou‐Ying Li Yung‐Chieh Lin Prof. Jia‐Cherng Horng Dr. Shwu‐Chen Tsay 《化学:亚洲杂志》2014,9(12):3408-3412
For the first time ssDNA (25‐aptamer of mixed dA, dT, dG, and dC) was wrapped around functionalized single‐walled carbon nanotubes (SWCNTs), whose external surfaces were attached to multiple triazole‐(ethylene glycol)‐dA ligands. This method of hybridization involved the formation of hydrogen bonds between dT of ssDNA and dA of functionalized SWCNTs. It deviates from the reported π–π stacking between the nucleobases of DNA and the external sidewalls of nanotubes. The structural properties of the functionalized SWCNTs and its ssDNA complex were characterized by spectroscopic (including CD and Raman), thermogravimetric, and microscopic (TEM) methods. The results thus obtained establish a new platform of DNA delivery by use of nanotubes as a new vehicle with great potential in biomedical applications and drug development. 相似文献
102.
103.
P. P. Lee R. J. Hwu L. P. Sadwick H. Balasubramaniam B. R. Kumar J. H. Chern R. T. Lareau 《Physica E: Low-dimensional Systems and Nanostructures》1998,2(1-4)
Details of the structural and electrical properties of epitaxial DyP/GaAs and DyAs/GaAs is reported. DyP is lattice matched to GaAs, with a room temperature mismatch of less than 0.01%. DyAs, on the other hand, has a mismatch of nearly 2.4%. Both DyP and DyAs have been grown by solid source MBE using custom designed group V thermal cracker cells and group III high-temperature effusion cells. High-quality DyP and DyAs epilayers, as determined by XRD, TEM, and AFM analysis, were obtained for growth temperatures ranging from 500°C to 600°C with growth rates between 0.5 and 0.7 μm/h. The DyP epilayers are n-type with measured electron concentrations of the order of 3×1020 to 4×1020 cm−3, with room temperature mobilities of 250–300 cm2/V s, and with a barrier height of 0.75 eV to GaAs. The DyAs epilayers are also n-type with concentration of 1×1021 to 2×1021 cm−3, with mobilities between 25 and 40 cm2/V s. DyP is stable in air with no apparent oxidation taking place, even after months of ambient exposure to untreated air. 相似文献
104.
Stephen P. Taylor Mariusz Krawiec Shiou‐Jyh Hwu 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(3):i27-i28
Transparent yellow plates of rubidium manganese hexathiodiphosphate, Rb2MnP2S6, were synthesized in molten RbBr. The compound is isotypic to other compounds of the type A2MP2Q6 (A = K, Rb, Cs; M = Mn, Fe; Q = S, Se). Its structure can be viewed as columns of face‐sharing S6 polyhedra parallel to the a axis, interconnected by Rb+. The S6 polyhedra are centered alternately by Mn (in octahedral coordination) and P2 units (in trigonal antiprisms). The Mn atom and P2S6 group lie on centers of symmetry. 相似文献
105.
106.
A new family of cuprates, Li2Cu3(SiO3)4 (1) and Na2Cu3(GeO3)4 (2), was isolated in molten salt media. The extended lattices contain ladderlike periodic arrays of [Cu3O8]10- magnetic nanostructures. Magnetic properties of the Na2Cu3Ge(4-x)SixO12 series, where x = 0, 0.86, and 1.72, were systematically studied. The geometrically induced magnetic couplings are tunable upon cation substitution. 相似文献
107.
K. G. Sanjaya Ranmohotti Wendy L. Queen J. Palmer West Don VanDerveer Shiou-Jyh Hwu 《Journal of chemical crystallography》2009,39(4):303-307
Abstract A new barium chlorovanadate, Ba5(V2O7)2Cl2, was isolated by a high-temperature (850 °C) reaction employing a CsCl/RbCl flux. The structure was determined by single
crystal X-ray diffraction methods. This compound crystallizes in an orthorhombic crystal system, Pmmn (No. 59), with a = 11.558(2) ?, b = 15.164(3) ?, c = 10.023(2) ?, Z = 4 and V = 1756.7(6) ?3. The structure of Ba5(V2O7)2Cl2 was determined by full-matrix, least-squares methods with R
1 = 0.0398, wR
2 = 0.1069 and GOF = 1.048 for all data. This new structure can be described as a composite lattice made up of mixed covalent
and ionic moities. The extended framework is orchestrated by stacked [Ba(V2O7)Cl]3− slabs that are interconnected by Ba2+ cations through Ba–O bonds to the [V2O7] units. The Ba2+ and Cl- ions form BN-type “[BaCl]” sheets with pseudo-hexagonal windows that are centered by [V2O7]4− pyrovanadate units.
Graphical Abstract The structure of a new chlorovanadate, Ba5(V2O7)2Cl2, exhibits an interesting BN-type salt lattice that consists of an extended [BaCl] sheet containing pseudo-hexagonal windows
that are centered by [V2O7] pyrovanadate units.
相似文献
108.
Finite element simulation for estimating the mechanical properties of multi-walled carbon nanotubes 总被引:2,自引:0,他引:2
C. W. Fan Y. Y. Liu Chyanbin Hwu 《Applied Physics A: Materials Science & Processing》2009,95(3):819-831
A finite element simulation technique for estimating the mechanical properties of multi-walled carbon nanotubes is developed.
In the present modeling concept, individual carbon nanotube is simulated as a frame-like structure and the primary bonds between
two nearest-neighboring atoms are treated as beam elements, the beam element properties are determined via the concept of
energy equivalence between molecular dynamics and structural mechanics. As to the simulation of the interlayer van der Waals
force which has intrinsic nonlinearity and complicated applying region, a simplifying method is proposed that the interlayer
pressure caused by van der Waals force instead of the force itself is to be considered, and we make use of the linear part
of the interlayer pressure near the equilibrium condition to avoid the nonlinearity in problem, then linear spring elements
whose stiffness is determined by equivalent force concept can be utilized to simulate the interlayer van der Waals force such
that significant modeling and computing effort is saved in performing the finite element analysis. Numerical examples for
estimating the mechanical properties of nanotubes, such as axial and radial Young’s modulus, shear modulus, natural frequency,
buckling load, etc., are presented to illustrate the accuracy of this simulation technique. By comparing to the results found
in the literature and the possible analytical solutions, it shows that the obtained mechanical properties of nanotubes by
the present method agree well with their comparable results. In addition, the relations between these mechanical properties
and the nanotube size are also discussed. 相似文献
109.
Dr. Luca Sorrentino Dr. Federica Cossu Dr. Mario Milani Bilge Malkoc Dr. Wen-Chieh Huang Dr. Shwu-Chen Tsay Prof. Jih Ru Hwu Dr. Eloise Mastrangelo 《ChemistryOpen》2019,8(4):476-482
Inhibitors of Apoptosis Proteins (IAPs) are conserved E3-ligases that ubiquitylate substrates to prevent apoptosis and activate the NF-kB survival pathway, often deregulated in cancer. IAPs-mediated regulation of NF-kB signaling is based on the formation of protein complexes by their type-I BIR domains. The XIAP-BIR1 domain dimerizes to bind two TAB1 monomers, leading to downstream NF-kB activation. Thus, impairment of XIAP-BIR1 dimerization could represent a novel strategy to hamper cell survival in cancer. To this aim, we previously reported NF023 as a potential inhibitor of XIAP-BIR1 dimerization. Here we present a thorough analysis of NF023 binding to XIAP-BIR1 through biochemical, biophysical and structural data. The results obtained indicate that XIAP-BIR1 dimerization interface is involved in NF023 binding, and that NF023 overall symmetry and the chemical features of its central moiety are essential for an efficient interaction with the protein. Such strategy provides original hints for the development of novel BIR1-specific compounds as pro-apoptotic agents. 相似文献
110.
Design and performance of an X‐ray scanning microscope at the Hard X‐ray Nanoprobe beamline of NSLS‐II 下载免费PDF全文
E. Nazaretski H. Yan K. Lauer N. Bouet X. Huang W. Xu J. Zhou D. Shu Y Hwu Y. S. Chu 《Journal of synchrotron radiation》2017,24(6):1113-1119
A hard X‐ray scanning microscope installed at the Hard X‐ray Nanoprobe beamline of the National Synchrotron Light Source II has been designed, constructed and commissioned. The microscope relies on a compact, high stiffness, low heat dissipation approach and utilizes two types of nanofocusing optics. It is capable of imaging with ~15 nm × 15 nm spatial resolution using multilayer Laue lenses and 25 nm × 26 nm resolution using zone plates. Fluorescence, diffraction, absorption, differential phase contrast, ptychography and tomography are available as experimental techniques. The microscope is also equipped with a temperature regulation system which allows the temperature of a sample to be varied in the range between 90 K and 1000 K. The constructed instrument is open for general users and offers its capabilities to the material science, battery research and bioscience communities. 相似文献