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21.
A Terenzi C Ducani V Blanco L Zerzankova AF Westendorf C Peinador JM Quintela PJ Bednarski G Barone MJ Hannon 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(35):10983-10990
The interaction with native DNA of a 2,7-diazapyrenium-based ligand 1 and its Pt(II) rectangular metallacycle 2 is explored through circular and linear dichroism and fluorescence spectroscopies. The metal-free ligand 1 binds through intercalation, with a binding constant of approximately 5×10(5) M(-1) , whereas the metallacycle 2 binds and bends the DNA with a binding constant of 7×10(6) M(-1) . PCR assays show that metallo-supramolecular box 2 interferes with DNA transactions in vitro whereas the intercalator 1 does not. The metallacycle is active against four human cancer cell lines, with IC(50) values ranging between 3.1 and 19.2?μM and shows similar levels of efficacy, but a different spectrum of activity, to cisplatin. 相似文献
22.
C Chirivì G Fontana D Monti G Ottolina S Riva B Danieli 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(33):10355-10361
Laccase-catalysed oxidation of ergot alkaloids in the absence of chemical mediators allowed the unexpected isolation of the mono-hydroxylated derivatives of compounds 2-7. Structure determination by NMR techniques clearly indicated that hydroxylation took place at the C-4 benzylic position. Quite notably, the proposed protocol allowed, for the first time, functionalisation at the C-4 position of the ergoline skeleton. Depending on the absence or on the presence of a C-10 α-methoxy substituent, hydroxylation was either stereoselective (furnishing C-4α OH derivatives) or gave rise to a C-4α/C-4β OH mixture in a 2:1 ratio, respectively. 相似文献
23.
Cosimo Bambi 《理论物理通讯》2009,52(1):78-80
The possibility of stable or quasi-stable Planck mass black hole remnants as solution to the black hole information paradox is commonly believed phenomenologically unacceptable. Since we need a black hole remnant for every possible initial state,the number of remnants is expected to be infinite and that would lead to remnant pair production in any physical process with a total available energy roughly exceeding the Planck mass. In this note I point out that a positive cosmological constant of the Universe would naturally lead to an upper bound on the numberof possible remnants. 相似文献
24.
Marcella Niglio Cosimo Damiano Vitale 《Methodology and Computing in Applied Probability》2012,14(1):17-34
In this paper the (strict and weak) stationarity of threshold autoregressive moving average models is discussed. After examining
the strict stationarity, mainly based on the random coefficient autoregressive representation of the model, we provide sufficient
conditions for its weak stationarity that allow to obtain a wider stationarity region with respect to some previous results
given in the literature. These conditions are discussed to distinguish between global and local stationarity, whose relation has been considered in detail. The threshold process has been further evaluated to face the
problem related to the so called existence of a threshold structure in the data generating process that is strictly related to the stationarity and has significant
relevance when the parameters of the model have to be estimated. 相似文献
25.
Carlo Battistini Cosimo Scarafile Maurizio Foglio Giovanni Franceschi 《Tetrahedron letters》1984,25(22):2395-2398
A new ring closure by carbonyl-carbonyl reductive coupling is utilized in the synthesis of penem and carbapenem nuclei. 相似文献
26.
Maurizio Avella Roberto Avolio Irene Bonadies Cosimo Carfagna Maria Emanuela Errico Gennaro Gentile 《Journal of Thermal Analysis and Calorimetry》2010,102(3):975-982
Dynamic thermogravimetric analysis under nitrogen flow was used to investigate the thermal decomposition process of high-density
poly(ethylene) (HDPE)-based composites reinforced with cellulose fibers obtained from the recycling of multilayer carton scraps,
as a function of the cellulose content and the compatibilization. The Friedman, Flynn–Wall–Ozawa, and Coats–Redfern methods
were used to determine the apparent activation energy (E
a) of the thermal degradation of the cellulose component into the composites. E
a has been found dependent on the cellulose amount and on the cellulose/polymer matrix interfacial adhesion. In particular,
it has been evidenced an increase of the cellulose thermal stability as a consequence of the improved interfacial adhesion
between the components in NFR composites. 相似文献
27.
Filippo Samperi Salvatore Battiato Concetto Puglisi Andrea Scamporrino Veronica Ambrogi Laura Ascione Cosimo Carfagna 《Journal of polymer science. Part A, Polymer chemistry》2011,49(16):3615-3630
Linear–hyperbranched hybrid poly(butylene adipate) (HPBA) copolymers were synthesized through a branching reaction between the linear tailored prepolymer terminated with methyl ester groups and different mol percents of the 1,1,1‐tris(hydroxymethyl) propane (TMP) as branching agent, using the titanium(IV) isopropoxide as catalyst, at 180 °C under vacuum for different times. All samples were characterized by NMR and matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI‐TOF MS). In particular, MALDI‐TOF mass spectra of the unfractionated and size exclusion chromatography (SEC)‐fractionated hyperbranched (HB) samples gave information on their composition, on the end groups as well as on the TMP units present in each family of HB macromolecules. HB chains containing cyclic branches and ether bonds formed by intermolecular transesterification and intramolecular and intermolecular transetherification side reactions, respectively, were also revealed by MALDI‐TOF MS analysis. All samples were also investigated by SEC. The average molar masses (MMs) evaluated by SEC calibrated with the polystyrene (PS) narrow standards were overestimated with respect to those calculated by the SEC/MALDI‐TOF MS self‐ calibration method, which gave reliable values. Moreover, it also showed that the hydrodynamic volume of the HPBA polymers was higher than that of the linear PSs with similar MMs. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
28.
Cosimo Altomare Pierre-Alain Carrupt Nabil El Tayar Bernard Testa Toshiharu Nagatsu 《Helvetica chimica acta》1991,74(2):290-296
A number of isomers and analogs of the neurotoxin 1-methyl-4-phenylpyridinium (MPP+) were examined for their lipophilic behavior. Their partition coefficients in the 1-octanol/H2O system were measured by centrifugal partition chromatography (CPC), which, being much faster and markedly more precise than the classical shake-flask method, proved a very promising alternative for assessing lipophilicity. A smaller-than-expected lipophilicity was shown by the ortho-isomer of MPP+ (M2PP+) and is explained in terms of electronic effects and rigidity, as revealed by UV and NMR spectroscopy, and conformational analysis. Implications of lipophilicity in modulating the in vivo dopaminergic neurotoxicity of the examined compounds are also discussed. 相似文献
29.
Rosa Purgatorio Nicola Gambacorta Modesto de Candia Marco Catto Mariagrazia Rullo Leonardo Pisani Orazio Nicolotti Cosimo D. Altomare 《Molecules (Basel, Switzerland)》2021,26(17)
Recently, the direct thrombin (thr) inhibitor dabigatran has proven to be beneficial in animal models of Alzheimer’s disease (AD). Aiming at discovering novel multimodal agents addressing thr and AD-related targets, a selection of previously and newly synthesized potent thr and factor Xa (fXa) inhibitors were virtually screened by the Multi-fingerprint Similarity Searching aLgorithm (MuSSeL) web server. The N-phenyl-1-(pyridin-4-yl)piperidine-4-carboxamide derivative 1, which has already been experimentally shown to inhibit thr with a Ki value of 6 nM, has been flagged by a new, upcoming release of MuSSeL as a binder of cholinesterase (ChE) isoforms (acetyl- and butyrylcholinesterase, AChE and BChE), as well as thr, fXa, and other enzymes and receptors. Interestingly, the inhibition potency of 1 was predicted by the MuSSeL platform to fall within the low-to-submicromolar range and this was confirmed by experimental Ki values, which were found equal to 0.058 and 6.95 μM for eeAChE and eqBChE, respectively. Thirty analogs of 1 were then assayed as inhibitors of thr, fXa, AChE, and BChE to increase our knowledge of their structure-activity relationships, while the molecular determinants responsible for the multiple activities towards the target enzymes were rationally investigated by molecular cross-docking screening. 相似文献
30.
A series of epoxy‐terminated liquid crystalline oligomers with different molecular weights having α‐methylstilbene as the mesogenic unit were synthesized and characterized by means of 1H NMR and FT‐IR spectroscopy, differential scanning calorimetry (DSC), polarized‐light optical microscopy (POM) and X‐ray diffraction. The effect of the initial ratio between epichlorohydrin and diol on the molecular weight was not significant enough to change the thermal behavior of the oligomers essentially. The copolymerization of epoxy‐ and hydroxyl‐terminated comonomers yielded high‐molecular weight oligomer, whose enantiotropic liquid crystalline character was proved by means of DSC, POM and X‐ray diffraction. 相似文献