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排序方式: 共有136条查询结果,搜索用时 62 毫秒
31.
U. Coscia G. Ambrosone A. Ambrosio M. Ambrosio F. Bussolotti V. Carillo V. Grossi P. Maddalena M. Passacantando E. Perillo A. Raulo S. Santucci 《Solid State Sciences》2009,11(10):1806-1809
Structural, optical and electrical properties of multiwalled carbon nanotubes deposited by chemical vapour deposition at 750 °C on sapphire substrate have been investigated. The main results concern the photoconductivity measurements. The photocurrent induced by white light illumination is a linear function of either the bias voltage or the optical power density in wide ranges. The photoresponse increases from the near infrared to the ultraviolet region with decreasing the wavelength of the monochromatic incident radiation in the 325–850 nm range. The photoresponse is strongly correlated to the optical absorbance. The optical and photoconductivity properties explored in multiwalled carbon nanotube samples with relatively large area appear very interesting for the development of light sensors. 相似文献
32.
Maddalena Corsini Piero Zanello Renzo Cini Gabriella Tamasi 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(6):m219-m223
The title compound, [Cu(C10H9N2O)2] or [CuII(CYMB)2], (I), was obtained in an attempt to reduce trans‐bis(2‐{[3,5‐bis(trifluoromethyl)phenyl]iminomethyl}phenolato)copper(II), [Cu(TIMB)2], (II), with bis(pentamethylcyclopentadienyl)cobalt(II) [decamethylcobaltocene, Cp*2Co, (III)]. The molecular structure of (I) has the CuII centre located on an inversion centre of the C2/c space group. A density functional theory (DFT) analysis at the B3LYP/Lanl2dz(CuF);6‐31G**(CHNO) level performed in order to optimize the structures of the free ligands CYMB− and TIMB−, and the metal complexes [CuI/II(CYMB)2]−/0 and [CuI/II(TIMB)2]−/0, reproduced well the X‐ray diffraction structure and allowed us to infer the insertion of the cyanomethide anion on the 3,5‐bis(trifluoromethyl)phenyl system from an evaluation of the Mulliken atomic charges and the electronic energies. 相似文献
33.
S Piccinonna N Margiotta C Pacifico A Lopalco N Denora S Fedi M Corsini G Natile 《Dalton transactions (Cambridge, England : 2003)》2012,41(32):9689-9699
Geminal bisphosphonates (BPs), used in the clinic for the treatment of hypercalcaemia and skeletal metastases, have been also exploited for promoting the specific accumulation of platinum antitumor drugs in bone tissue. In this work, the platinum dinuclear complex [{Pt(en)}(2)(μ-AHBP-H(2))](+) (1) (the carbon atom bridging the two phosphorous atoms carrying a 2-ammonioethyl and a hydroxyl group, AHBP-H(2)) has been used as scaffold for the synthesis of a Pt(II) trinuclear complex, [{Pt(en)}(3)(μ-AHBP)](+) (2), and a Pt(IV) adamantane-shaped dinuclear complex featuring an oxo-bridge, [{Pt(IV)(en)Cl}(2)(μ-O)(μ-AHBP-H(2))](+) (3) (X-ray structure). Compound 2 undergoes a reversible, pH dependent, rearrangement with a neat switch point around pH = 5.4. Compound 3 undergoes a one-step electrochemical reduction at E(pc) = -0.84 V affording compound 1. Such a potential is far lower than that of glutathione (-0.24 V), nevertheless compound 3 can undergo chemical reduction to 1 by GSH, most probably through a different (inner-sphere) mechanism. In vitro cytotoxicity of the new compounds, tested against murine glioma (C6) and human cervix (HeLa) and hepatoma (HepG2) cell lines, has shown that, while the Pt(IV) dimer 3 is inactive up to a concentration of 50 μM, the two Pt(II) polynuclear compounds 1 and 2 have a cytotoxicity comparable to that of cisplatin with the trinuclear complex 2 generally more active than the dinuclear complex 1. 相似文献
34.
Dacarro G Cucca L Grisoli P Pallavicini P Patrini M Taglietti A 《Dalton transactions (Cambridge, England : 2003)》2012,41(8):2456-2463
A polyethylenimine (PEI) self-assembled monolayer (SAM) is prepared, capable of complexing silver and copper cations and of anchoring silver nanoparticles, exerting antibacterial activity against Escherichia coli and Staphylococcus aureus. Functionalized glassy surfaces have been fully characterized through spectroscopic techniques (UV-Vis spectroscopy, spectroscopic ellipsometry), atomic force microscopy imaging and quantitative Ag and Cu analysis (ICP optical emission spectroscopy). 相似文献
35.
Maddalena Cavicchioli 《Discrete Applied Mathematics》2012,160(7-8):1253-1256
36.
In this paper, we propose a mathematical model with time delay to describe the process of diffusion of a new technology. This model is suitable for modeling diffusion processes of all those technologies that require great initial investments and public subsidies, such as technologies used for producing renewable energy. We consider external factors, such as the government policy and the production costs, that influence the decision of adoption of the new technology. We also consider the internal influence from adopters. The adoption process is described by a delay differential equation. The time delay represents the evaluation stage at which the potential consumers decide whether to adopt the new technology or not. A qualitative analysis is carried out in order to assess the stability of the equilibrium for certain parameters and to find the final level of adopters. 相似文献
37.
Uhrmacher M. Kulinska A. Baldokhin Yu. V. Tcherdyntsev V. V. Kaloshkin S. D. Maddalena A. Principi G. 《Hyperfine Interactions》2001,136(3-8):327-332
Hyperfine Interactions - High-energy ball milling of Fe–Mn elemental powder mixtures has been carried out for different Mn concentrations, ranging from 0 to 90%. Mössbauer spectroscopy... 相似文献
38.
Maurizio Viale Giovanni Lentini Rosaria Gangemi Patrizio Castagnola Gualtiero Milani Silvia Ravera Nadia Bertola Antonio Carrieri Maria Maddalena Cavalluzzi 《Molecules (Basel, Switzerland)》2022,27(22)
In a previous paper, we demonstrated the synergistic action of the anti-ischemic lubeluzole (Lube S) on the cytotoxic activity of doxorubicin (Dox) and paclitaxel in human ovarian cancer A2780 and lung cancer A549 cells. In the present paper, we extended in vitro the study to the multi-drug-resistant A2780/DX3 cell line to verify the hypothesis that the Dox and Lube S drug association may potentiate the antitumor activity of this anticancer compound also in the context of drug resistance. We also evaluated some possible mechanisms underlying this activity. We analyzed the antiproliferative activity in different cancer cell lines. Furthermore, apoptosis, Dox accumulation, MDR1 downregulation, ROS, and NO production in A2780/DX3 cells were also evaluated. Our results confirm that Lube S improves Dox antiproliferative and apoptotic activities through different mechanisms of action, all of which may contribute to the final antitumor effect. Moderate stereoselectivity was found, with Lube S significantly more effective than its enantiomer (Lube R) and the corresponding racemate (Lube S/R). Docking simulation studies on the ABCB1 Cryo-EM structure supported the hypothesis that Lube S forms a stable MDR1-Dox-Lube S complex, which hampers the protein transmembrane domain flipping and blocks the efflux of Dox from resistant A2780/DX3 cells. In conclusion, our in vitro studies reinforce our previous hypothesis for repositioning the anti-ischemic Lube S as a potentiating agent in anticancer chemotherapy. 相似文献
39.
Monica Ermolli Anna Fantozzi Massimiliano Marini Domenico Scotti Branko Balla Sebastian Hoffmann Maddalena Querci Claudia Paoletti Guy Van den Eede 《Accreditation and quality assurance》2006,11(1-2):55-57
GMO protein content in maize flours or fresh crops can be easily assessed by the enzyme-linked immunosorbent assays (ELISA)
and immunochromatographic (lateral flow) strip tests commercially available. Therefore, ELISA can be seen as a useful tool
for screening, for control purposes and for traceability implementation. In order to highlight the importance of monitoring
GMO protein presence in food products and to investigate the performance of representative ELISA commercial kits, we evaluated
three commercial kits by measuring the amount of Cry1Ab/Cry1Ac in IRMM certified reference materials.
Presented at AOAC Europe/Eurachem Symposium March 2005, Brussels, Belgium 相似文献
40.
P. Palade G. Principi S. Sartori A. Maddalena S. Lo Russo G. Schinteie V. Kuncser G. Filoti 《Hyperfine Interactions》2006,168(1-3):1029-1035
Mg–Ni–Fe magnesium-rich intermetallic compounds were prepared following two distinct routes. A Mg88Ni11Fe1 sample (A) was prepared by melt spinning Mg–Ni–Fe pellets and then by high-energy ball milling for 6 h the obtained ribbons. A (MgH2)88Ni11Fe1 sample (B) was obtained by high-energy ball milling for 20 h a mixture of Ni, Fe and MgH2 powders in the due proportions. A SPEX8000 shaker mill with a 10:1 ball to powder ratio was used for milling in argon atmosphere. The samples were submitted to repeated hydrogen absorption/desorption cycles in a Sievert type gas–solid reaction controller at temperatures in the range 520?÷?590 K and a maximum pressure of 2.5 MPa during absorption. The samples were analysed before and after the hydrogen absorption/desorption cycles by X-ray diffraction and Mössbauer spectroscopy. The results concerning the hydrogen storage properties of the studied compounds are discussed in connection with the micro-structural characteristics found by means of the used analytical techniques. The improved kinetics of hydrogen desorption for sample A, in comparison to sample B, has been ascribed to the different behaviour of iron atoms in the two cases, as proved by Mössbauer spectroscopy. In fact, iron results homogeneously distributed in sample A, partly at the Mg2Ni grain boundaries, with catalytic effect on the gas–solid reaction; in sample B, instead, iron is dispersed inside the hydride powder as metallic iron or superparamagnetic iron. 相似文献