排序方式: 共有81条查询结果,搜索用时 15 毫秒
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Dr. Nicoló Zuin Fantoni Dr. Zara Molphy Sinéad O'Carroll Dr. Georgia Menounou Dr. George Mitrikas Dr. Marios G. Krokidis Dr. Chryssostomos Chatgilialoglu Dr. John Colleran Dr. Anna Banasiak Prof. Martin Clynes Dr. Sandra Roche Suainibhe Kelly Prof. Vickie McKee Prof. Andrew Kellett 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(3):971-983
We report a series of copper(II) artificial metallo-nucleases (AMNs) and demonstrate their DNA damaging properties and in-vitro cytotoxicity against human-derived pancreatic cancer cells. The compounds combine a tris-chelating polypyridyl ligand, di-(2-pycolyl)amine (DPA), and a DNA intercalating phenanthrene unit. Their general formula is Cu-DPA-N,N' (where N,N'=1,10-phenanthroline (Phen), dipyridoquinoxaline (DPQ) or dipyridophenazine (DPPZ)). Characterisation was achieved by X-ray crystallography and continuous-wave EPR (cw-EPR), hyperfine sublevel correlation (HYSCORE) and Davies electron-nuclear double resonance (ENDOR) spectroscopies. The presence of the DPA ligand enhances solution stability and facilitates enhanced DNA recognition with apparent binding constants (Kapp) rising from 105 to 107 m −1 with increasing extent of planar phenanthrene. Cu-DPA-DPPZ, the complex with greatest DNA binding and intercalation effects, recognises the minor groove of guanine–cytosine (G-C) rich sequences. Oxidative DNA damage also occurs in the minor groove and can be inhibited by superoxide and hydroxyl radical trapping agents. The complexes, particularly Cu-DPA-DPPZ, display promising anticancer activity against human pancreatic tumour cells with in-vitro results surpassing the clinical platinum(II) drug oxaliplatin. 相似文献
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A degradable atom transfer radical polymerization inimer: Synthesis,polymerization, and cleavage of the resulting polymer products 下载免费PDF全文
Marios Elladiou Costas S. Patrickios 《Journal of polymer science. Part A, Polymer chemistry》2017,55(17):2831-2839
A novel degradable inimer for atom transfer radical polymerization (ATRP), 2‐(6‐(2‐((2‐bromo‐2‐methylpropanoyl)oxy)ethyl)pyridin‐2‐yl)ethyl methacrylate (PyDEBrMΑ), was synthesized by the two‐step esterification of 2,6‐pyridinediethanol, first with α‐bromoisobutyryl bromide in order to introduce the initiator moiety, and then with methacryloyl chloride in order to introduce the monomer moiety. PyDEBrMA was subsequently used to initiate the self‐condensing ATRP of methyl methacrylate (MMA) to obtain a hyperbranched MMA homopolymer which could be cleaved at the PyDEBrMA residue either by treatment under mildly alkaline hydrolysis conditions (sodium deuteroxide in d6‐DMSO at room temperature) or thermolysis at 150 °C. The lability of the PyDEBrMA residue arises from the presence in its structure of two 2‐(pyridin‐2‐yl)ethyl ester moieties. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 2831–2839 相似文献
4.
Jeff T. Gostick Marios A. Ioannidis Michael W. Fowler Mark D. Pritzker 《Electrochemistry communications》2009,11(3):576-579
The condition of liquid water breakthrough at the cathode of polymer electrolyte fuel cells (PEMFC) is studied experimentally and data on corresponding water saturation and capillary pressure are provided for gas diffusion layers (GDL) with and without a microporous layer (MPL). The data demonstrate that the GDL saturation at water breakthrough is drastically reduced from ca. 25% to ca. 5% in the presence of MPL. This observation is consistent with considerations of invasion percolation in finite-size lattices and suggests an explanation for the role of MPL in improving PEMFC performance at high current densities. 相似文献
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Sultana Ferdous Marios A. Ioannidis Dale Henneke 《Journal of nanoparticle research》2011,13(12):6579-6589
The pendant drop technique was used to characterize the adsorption behavior of n-dodecane-1-thiol and n-hexane-1-thiol-capped gold nanoparticles at the hexane–water interface. The adsorption process was studied by analyzing the
dynamic interfacial tension versus nanoparticle concentration, both at early times and at later stages (i.e., immediately
after the interface between the fluids is made and once equilibrium has been established). A series of gold colloids were
made using nanoparticles ranging in size from 1.60 to 2.85 nm dissolved in hexane for the interfacial tension analysis. Following
free diffusion of nanoparticles from the bulk hexane phase, adsorption leads to ordering and rearrangement of the nanoparticles
at the interface and formation of a dense monolayer. With increasing interfacial coverage, the diffusion-controlled adsorption
for the nanoparticles at the interface was found to change to an interaction-controlled assembly and the presence of an adsorption
barrier was experimentally verified. At the same bulk concentration, different sizes of n-dodecane-1-thiol nanoparticles showed different absorption behavior at the interface, in agreement with the findings of Kutuzov
et al. (Phys Chem Chem Phys 9:6351–6358, 2007). The experiments additionally demonstrated the important role played by the capping agent. At the same concentration, gold
nanoparticles stabilized by n-hexane-1-thiol exhibited greater surface activity than gold nanoparticles of the same size stabilized by n-dodecane-1-thiol. These findings contribute to the design of useful supra-colloidal structures by the self-assembly of alkane-thiol-capped
gold nanoparticles at liquid–liquid interfaces. 相似文献
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An experimental and theoretical study of butyl methacrylate in situ radical polymerization kinetics in the presence of graphene oxide nanoadditive 下载免费PDF全文
Marios Michailidis George D. Verros Eleni A. Deliyanni Eleftherios G. Andriotis Dimitris S. Achilias 《Journal of polymer science. Part A, Polymer chemistry》2017,55(8):1433-1441
The butyl methacrylate radical polymerization kinetics in the presence of graphene oxide nanoadditive is studied both experimentally and theoretically. The experimental study includes the formation of graphite oxide from the oxidation of graphite and its subsequent transformation to graphene oxide (GO) after ultrasonication and in situ polymerization. Monomer conversion versus time was monitored gravimetrically at various reaction temperatures and initial GO fractions. Formation of GO was verified by X‐ray diffraction spectra and the number and weight average molecular weights of the final polymer were obtained from GPC measurements. A detailed theoretical kinetic model was further developed. The model predictions were found to be in satisfactory agreement with the experimental data. The presence of GO was found to result in reduced initiator efficiency verified theoretically and explained through side reactions of primary radicals. Finally, nanocomposites showed enhanced thermal stability compared to neat PBMA. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 1433–1441 相似文献
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Sotirios Zarogiannis Vassilios Liakopoulos Chrissi Hatzoglou Konstantinos Vogiatzidis Marios Salmas Ioannis Stefanidis Konstantinos Gourgoulianis Paschalis Adam Molyvdas Spiros Lafis 《Analytical sciences》2007,23(5):593-595
This article reports on the development of a simple and cost-effective bioassay for the detection of biotin in urine and serum, based on the very selective binding of avidin and biotin. Avidin was allowed to react without isolating it from egg white. Egg white was treated with the dye HABA, which binds to avidin. Upon subsequent treatment with biotin, HABA is released due to the high affinity of biotin to avidin. The amount of HABA released is proportional to the amount of biotin used. 相似文献
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Steady convective mass transfer to or from fluid interfaces in pores of angular cross-section is theoretically investigated.
This situation is relevant to a variety of mass transport process in porous media, including the fate of residual non-aqueous
phase liquid ganglia and gas bubbles. The model incorporates the essential physics of capillarity and solute mass transfer
by convection and diffusion in corner fluid filaments. The geometry of the corner filaments, characterized by the fluid–fluid
contact angle, the corner half-angle and the interface meniscus curvature, is accounted for. Boundary conditions of zero surface
shear (‘perfect-slip’) and infinite surface shear (‘no-slip’) at the fluid–fluid interface are considered. The governing equations
for laminar flow within the corner filament and convective diffusion to or from the fluid–fluid interface are solved using
finite-element methods. Flow computations are verified by comparing the dimensionless resistance factor and hydraulic conductance
of corner filaments against recent numerical solutions by Patzek and Kristensen (J. Colloid Interface Sci 236, 305–317 2001). Novel results are obtained for the average effluent concentration as a function of flow geometry and pore-scale
Peclet number. These results are correlated to a characteristic corner length and local pore-scale Peclet number using empirical
equations appropriate for implementation in pore network models. Finally, a previously published “2D-slit” approximation to
the problem at hand is checked and found to be in considerable error. 相似文献
9.
Marios Kosmas Thomas Forzaglia Marvin Bishop 《Macromolecular theory and simulations》2011,20(9):806-813
The various end‐to‐end distances of four‐junction polymers are investigated. The sizes of the different kinds of equal length branches and the backbone of two different polymers, with either nine or eleven branches, are estimated by means of both renormalization‐group and MC calculations. The comparisons of first‐order ε = 4 − d predictions with the MC results are satisfactory. The same trends are present in both techniques. The excluded‐volume interactions from additional branches further expand the various parts of the chains so that internal branches are larger than external ones. The branch ratios in the eleven‐branch case are expanded even more than the corresponding ratios of the nine‐branch polymer.
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We investigate polymer stretching by fluctuating flow fields via numerical solutions of the Brownian dynamics of multibead polymer chains taking into account nonlinear elasticity, hydrodynamic interactions and good solvent, excluded volume interaction effects. By varying the scaling exponent of the energy spectrum whilst keeping the same Reynolds and Deborah numbers, as well as microscale length and turnover times, we show that steeper spectra are associated with stronger stretching. We compute the probability density functions of chain length, and explain their main features by examining explicit molecular histories. We quantify the interaction between strain rate tensor structure and chain geometry as a means of understanding better the different stretching mechanisms in mild, moderate and strong polymer stretching regimes. 相似文献