排序方式: 共有74条查询结果,搜索用时 15 毫秒
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Radostina Kalinova Miroslava Valchanova Ivaylo Dimitrov Sevdalina Turmanova Iva Ugrinova Maria Petrova Zlatina Vlahova Stanislav Rangelov 《International journal of molecular sciences》2021,22(17)
Gene therapy is an attractive therapeutic method for the treatment of genetic disorders for which the efficient delivery of nucleic acids into a target cell is critical. The present study is aimed at evaluating the potential of copolymers based on linear polyglycidol to act as carriers of nucleic acids. Functional copolymers with linear polyglycidol as a non-ionic hydrophilic block and a second block bearing amine hydrochloride pendant groups were prepared using previously synthesized poly(allyl glycidyl ether)-b-polyglycidol block copolymers as precursors. The amine functionalities were introduced via highly efficient radical addition of 2-aminoethanethiol hydrochloride to the alkene side groups. The modified copolymers formed loose aggregates with strongly positive surface charge in aqueous media, stabilized by the presence of dodecyl residues at the end of the copolymer structures and the hydrogen-bonding interactions in polyglycidol segments. The copolymer aggregates were able to condense DNA into stable and compact nanosized polyplex particles through electrostatic interactions. The copolymers and the corresponding polyplexes showed low to moderate cytotoxicity on a panel of human cancer cell lines. The cell internalization evaluation demonstrated the capability of the polyplexes to successfully deliver DNA into the cancer cells. 相似文献
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In this work, erbium, and erbium and ytterbium co-doped YVO4 waveguiding thin films were deposited on amorphous SiO2 substrates by pulsed laser deposition (PLD) and ultraviolet-assisted pulsed laser deposition (UVPLD). The influence of the deposition technique on the structure, morphology, and optical properties of the films was investigated. At lower dopant concentrations the films prepared by UVPLD show better crystallinity and optical properties. All the samples show preferred orientation of the (001) zone axes parallel to the substrate surface. The polycrystalline samples show difference in the refractive indexes ?n (?n = nTE − nTM) for the TE and TM polarizations. 相似文献
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The propagation of optical beams in optical thin films grown by pulsed laser deposition is studied numerically in order to predict the influence of the film curvature on the performance of planar waveguide lasers. Several waveguiding structures are considered. The confinement of both the pump and the signal fields as well the overlap between the beams during propagation are examined. 相似文献
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Jií Franc Jan Hlvka Stanislav Neprek Ivaylo Zhivkov 《Solar Energy Materials & Solar Cells》2006,90(17):2924-2933
Photosensitive powders of CdS were prepared with different concentrations of dopants. Doses of donors (Cl−) and acceptors (Cu2+, Ag+) varied from 0 to 41 and from 0 to 9 mg/g CdS, respectively. Reflectance, absorption coefficient and resistance dependence on illumination intensity and voltage at the wavelength of about λ=630 nm and photovoltage spectra in the range 450–900 nm were measured on layers prepared from the powders. The value of absorption coefficient grew with the increasing dopant concentrations; acceptors appeared more efficient than donors. Reflectance decreased with growing acceptor dose. Using the values of reflectance, absorption coefficient and resistance the corrected photovoltage, as the measure of the concentration photogenerated charge carriers, was calculated. The ratio (σIGB) of the corrected photovoltage and photocurrent was used as the criterion of intergrain barrier conductivity. All doped samples exhibited similar value of σIGB which was about three orders of magnitude lower than that of undoped sample. 相似文献
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Ouar Nassima Farhat Samir Mercone Silvana Zighem Fatih Schoenstein Frédéric Jouini Noureddine Hinkov Ivaylo Wang Guillaume Ricolleau Christian 《American Institute of Chemical Engineers》2015,61(1):304-316
Bimetallic one‐dimensional cobalt–nickel magnetic nanowires capped on both sides with conical heads were synthesized using the polyol process. Then, the process was scaled up to produce magnetic nanowires in sample aliquots of approximately 20 g. The scale‐up strategy involved improving the mixing reagents using either axial or radial mixing configurations and was experimentally validated by comparing the structural and magnetic properties of the resulting nanowires. The results indicated a connection between the flow patterns and the size and shape of the nanowires. When a Rushton turbine was used, shorter nanowires with unconventional small heads were obtained. Because the demagnetizing field is strongly localized near or inside these heads, the coercive field was enhanced nearly twofold. These results were confirmed by micromagnetic simulations using isolated nanowires. In addition, the development of flow patterns at the small and pilot scales was predicted and compared using three‐dimensional turbulent computational fluid dynamics simulations. © 2014 American Institute of Chemical Engineers AIChE J, 61: 304–316, 2015 相似文献
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Ivaylo N. Vladimirov Stefanie Reese 《International Journal of Mechanical Sciences》2009,51(4):305-313
This paper focuses on the modelling of primary, secondary and tertiary creep of nickel-base single crystal superalloys at high temperatures. In particular, we propose an extension of the Cailletaud single crystal plasticity model [Méric L, Poubanne P, Cailletaud G. Single crystal modeling for structural calculations: part I—model presentation. Transactions of the ASME 1991;133:162-170] to include tertiary creep. This is achieved by introducing an additional evolution equation for a scalar damage variable per slip system. In addition, a methodology for the calibration of the material parameters of the model to fit the results from experiments has been implemented. The parameter identification rests upon a two-membered evolution strategy. The comparison with uniaxial and multiaxial test data shows a good agreement between model and experiment. The structural simulations have been performed by means of a special element technology which enables efficient and accurate finite element computations. 相似文献
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Marinov V.R. Atanasov Y.A. Khan A. Vaselaar D. Halvorsen A. Schulz D.L. Chrisey D.B. 《IEEE sensors journal》2007,7(6):937-944
Functioning chemiresistor vapor sensing devices on plastic substrates were prepared using low-temperature direct-Xwrite techniques. Interdigitated Ag electrodes were first deposited onto printed circuit boards using a mesoscale maskless materials deposition system (M3D). These Ag lines were 20-50 mum wide and 8-10 mum thick with good adhesion to the substrate and electrical conductivity of 4-12 muOmegamiddotcm. Deposition of chemoselective polymer/C black composite transducer layers on such lines gave sensors that responded to nerve gas stimulant (dimethylmethyl phosphonate) thereby demonstrating the efficacy of direct write for this application. A new approach to localized direct-write deposition, termed Enhanced M3D, allows the formation of sharply defined line edges and enables printing of conductors that operate at radio frequency with low signal loss. The direct-write approaches described here are amenable to future deposition on more interesting substrates and development of more sensitive transducers, orthogonal sensor arrays and an integrated power source/communication platform that might constitute the basis for radio-frequency identification (RFID) sensor tags 相似文献
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Constituents of Mediterranean Spices Counteracting Vascular Smooth Muscle Cell Proliferation: Identification and Characterization of Rosmarinic Acid Methyl Ester as a Novel Inhibitor 下载免费PDF全文