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11.
Fang Xia S. Baccaro Wei Wang L. Pilloni Xianghua Zhang Huidan Zeng Guorong Chen 《Journal of Non》2008,354(12-13):1137-1141
Nanophase separation in the bulk Ge–As–Se chalcogenide glasses was observed by SEM and supported by XRD and IR measurements. Effects of nanophase separation on glass transition temperature (Tg), microhardness (Hv), optical band gap (Eopt) and thermal expansion coefficient (α) were investigated in terms of glass rigidity transitions. According to the correlations between the properties and average coordination number Z, it is established that nanophase separation becomes more intensive when Z is larger than 2.64. 相似文献
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G. Pilloni G. Zotti C. Corvaja M. Martelli 《Journal of Electroanalytical Chemistry》1978,91(3):385-392
The voltammetric behaviour of the new complex, [Ru(NO)(Ph2PCH2CH2CH2PPh2)2]+, has been studied in 1,2-dimethoxyethane and the results compared with those obtained in the analogous reduction of [Ru(NO)(Ph2PCH2PPh2)2]+. The reduction proceeds in two reversible, one-electron steps. Stepwise reduction of these cationic complexes leads to two reversible, one-electron steps. Stepwise reduction of these cationic complexes leads to anionic complexes with formal oxidation number (?II) through the intermediate state which, in the case of Ph2PCH2CH2PPh2 ligand, is unstable and decays via a disproportionation pathway. A reduction-oxidation mechanism accounting for the chemical and electrochemical results is proposed. 相似文献
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Gold dithiocarbamate derivatives as potential antineoplastic agents: design, spectroscopic properties, and in vitro antitumor activity 总被引:1,自引:0,他引:1
Ronconi L Giovagnini L Marzano C Bettìo F Graziani R Pilloni G Fregona D 《Inorganic chemistry》2005,44(6):1867-1881
At present, cisplatin (cis-diamminodichloroplatinum(II)) is one of the most largely employed anticancer drugs as it is effective in the treatment of 70-90% of testicular and, in combination with other drugs, of ovarian, small cell lung, bladder, brain, and breast tumors. Anyway, despite its high effectiveness, it exhibits some clinical problems related to its use in the curative therapy, such as a severe normal tissue toxicity (in particular, nephrotoxicity) and the frequent occurrence of initial and acquired resistance to the treatment. To obtain compounds with superior chemotherapeutic index in terms of increased bioavailability, higher cytotoxicity, and lower side effects than cisplatin, we report here on some gold(I) and gold(III) complexes with dithiocarbamate ligands (DMDT = N,N-dimethyldithiocarbamate; DMDTM = S-methyl-N,N-dimethyldithiocarbamate; ESDT = ethylsarcosinedithiocarbamate), which have been synthesized, purified, and characterized by means of elemental analyses, conductivity measurements, mono- and bidimensional NMR, FT-IR, and UV-vis spectroscopy, and thermal analyses. Moreover, the electrochemical properties of the designed compounds have been studied through cyclic voltammetry. All the synthesized gold complexes have been tested for their in vitro cytotoxic activity. Remarkably, most of them, in particular gold(III) derivatives of N,N-dimethyldithiocarbamate and ethylsarcosinedithiocarbamate, have been proved to be much more cytotoxic in vitro than cisplatin, with IC50 values about 1- to 4-fold lower than that of the reference drug, even toward human tumor cell lines intrinsically resistant to cisplatin itself. Moreover, they appeared to be much more cytotoxic also on the cisplatin-resistant cell lines, with activity levels comparable to those on the corresponding cisplatin-sensitive cell lines, ruling out the occurrence of cross-resistance phenomena and supporting the hypothesis of a different antitumor activity mechanism of action. 相似文献
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G. Pilloni G. Zotti Q.G. Mulazzani P.G. Fuochi 《Journal of Electroanalytical Chemistry》1982,137(1):89-102
The Electrochemical behaviour of a series of cationic hydrido-complexes of Fe(II) of general formula trans-[FeH(L)(DPE)2] (BPh4)(L=N2, C2H5N, C6H5CN, CH2CHCN, CH3CN, P(OCH3)3, P(OC2H5)3, CO; DPE=1,2- bis(diphenylphosphino)ethane) has been investigated in 1,2-dimethoxyethane at the platinum electrode. The reduction of these d6 complexes has been found to proceed by an ECE mechanism in which a one-electron transfer, generating a transient d7 species, is followed by the fast loss of one of the neutral ligands and a further one-electron reduction of the pentacoordinated intermediates to the final d8 anionic hydrides. The reduced species are stabilized considerably at low temperature. The ligands, L, are divided into two groups according to their bonding properties, with particular references to their ability to act as π- acceptors. Weak π-bonders (N2, C2H5N, C6H5CN, CH2CHCN, CH3CN) are lost in the chemical step interposed between the two charge-transfer processes, whereas strong π-accepting ligands (CO and P(OR)3) favour dissocia tion of one end of a diphosphine. 相似文献
15.
We reanalyze the recent computation of the amplitude of the Higgs boson decay into two photons presented by Gastmans et al. [1, 2]. The reasons for why this result cannot be the correct one have been discussed in some recent papers. We address here the general issue of the indeterminacy of integrals with four-dimensional gauge-breaking regulators and to which extent it might eventually be solved by imposing physical constraints. Imposing gauge invariance as the last step upon Rξ-gauge calculations with four-dimensional gauge-breaking regulators, allows us to recover the well known H→γγ result. However we show that in the particular case of the unitary gauge, the indeterminacy cannot be tackled in the same way. The combination of the unitary gauge with a cutoff regularization scheme turns out to be non-predictive. 相似文献
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The stability constants of the complexes of 1-(2-pyridylazo)-2-naphthol with several organotin and lead ions were determined spectrophotometrically in aqueous 20% (v/v) dioxane and were shown to have very high values. The extraction of the complex of (C2H5)2Pb2+ from water into chloroform was studied, and the formation of an extractable (C2H5)2Pb(PAN)(OH) complex is postulated. 相似文献
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Alessandra Scano Guido Ennas Francesca Frongia Aurelio La Barbera M. Arturo López-Quintela Giaime Marongiu Giorgio Paschina Davide Peddis Martina Pilloni Carlos Vázquez-Vázquez 《Journal of nanoparticle research》2011,13(7):3063-3073
Mn–ferrite nanoparticles were synthesized by thermal treatment at 800 °C of manganese and iron oxo-hydroxides obtained via
water-in-oil microemulsions consisting of n-hexanol as continuous phase, cetyl trimethyl ammonium bromide (CTAB) as the cationic surfactant and aqueous solutions of
metal salts and precipitant agent (tetramethyl ammonium hydroxide) as reagents. Nanoparticles were synthesized using a multi-microemulsion
approach. Two different co-precipitation routes are described depending on the Fe(II) or Fe(III) precursor salts. The influence
of salt concentration and digestion process on the final products was examined. The nanoparticles were characterized by X-ray
diffraction accompanied by Rietveld analysis, transmission electron microscopy, thermal analysis, infrared spectroscopy, and
SQUID magnetometry. In all the synthesis reported in this study MnFe2O4 was observed only after thermal treatment at 800 °C of the as-prepared precursors. Almost spherical nanocrystalline MnFe2O4 ranging from 12 to 39 nm was obtained starting from chlorides or mixed chloride–sulfate salts as precursors. Low values of
reduced remanent magnetization (M
r/M
s) and coercive field (H
c) induce to believe that a fraction of superparamagnetic particle is present at room temperature. 相似文献