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981.
982.
Letters in Mathematical Physics - We consider the Rosenzweig–Porter model $$H = V + \sqrt{T}\, \varPhi $$ , where V is a $$N \times N$$ diagonal matrix, $$\varPhi $$ is drawn from the $$N... 相似文献
983.
Cardoso-Lopes EM Maier JA da Silva MR Regasini LO Simote SY Lopes NP Pirani JR Bolzani Vda S Young MC 《Molecules (Basel, Switzerland)》2010,15(12):9205-9213
Esenbeckia leiocarpa Engl. (Rutaceae), popularly known as guarant?, goiabeira, is a native tree from Brazil. Bioactivity-guided fractionation of the ethanol stems extract afforded the isolation of six alkaloids: leiokinine A, leptomerine, kokusaginine, skimmianine, maculine and flindersiamine. All isolated compounds were tested for acetyl cholinesterase inhibition, in vitro and displayed anticholinesterasic activity. The alkaloid leptomerine showed the highest activity (IC?? = 2.5 mM), similar to that of the reference compound galanthamine (IC?? = 1.7 mM). The results showed for the first time the presence of alkaloids leptomerine and skimmianine in E. leiocarpa (Engl.) with potent anticholinesterasic activity. 相似文献
984.
Ciogli A D'Acquarica I Gasparrini F Molinaro C Rompietti R Simone P Villani C Zappia G 《Journal of separation science》2010,33(19):3022-3032
Two hybrid polyacrylamide chiral stationary phases (CSPs) for HPLC have been synthesized by a new surface-initiated photo-induced radical polymerization approach of enantiopure N,N'-diacryloyl derivatives of (1R,2R)-diaminocyclohexane (CSP1) and (1R,2R)-diphenylethylenediamine (CSP2). This system is based on the activation of mesoporous silica microparticles by chemically bonded trichloroacetyl groups and dimanganese decacarbonyl as catalyst. UV irradiation was performed using a lab-made quartz photochemical reactor, ad hoc designed for the photo-induced polymerization process on the surface of microparticles. The two phases were evaluated and compared as chromatographic supports for the enantioselective HPLC of model chiral compounds. Their physico-chemical properties and chromatographic performances were also evaluated in comparison with those exhibited by the homologue CSPs obtained by the grafting-from thermal-induced process (CSP3 and CSP4). The new photopolymerization approach yielded higher grafting density than the thermal-induced one, especially in the case of the less reactive monomer (the diacryloyl derivative of (1R,2R)-diphenylethylenediamine), good chromatographic efficiency and a broad application field under normal phase and polar organic mode conditions. 相似文献
985.
Lina Chianese Maria Grazia Calabrese Pasquale Ferranti Rosalba Mauriello Giuseppina Garro Carmela De Simone Maria Quarto Francesco Addeo Gianfranco Cosenza Luigi Ramunno 《Journal of chromatography. A》2010,1217(29):4834-4840
At present, compared with bovine milk, the characterization of donkey milk caseins is at a relatively early stage progress, and only limited data are related to its genetic polymorphism. In this work, the heterogeneity of donkey caseome was investigated using a proteomic approach, based on one- (PAGE, UTLIEF) and two-dimensional (PAGE → UTLIEF) electrophoresis, stained with either Coomassie Brilliant Blue or specific polyclonal antibodies, and structural MS analysis. These combined methodologies allowed the contemporary identification of donkey αs1, αs2, β and κ-CN with their related heterogeneity due to phosphorylation (αs1, αs2 and β-CN), glycosylation (κ-CN) and incorrect splicing of RNA in mRNA (deleted forms of αs1-CN and β-CN). The results achieved showed 11 components for κ-CN, six phosphorylated components for β and αs1-CN and three main phosphorylated components for αs2-CN, each accounting for 10, 11 and 12 P/mole. At this regard, for the first time, the primary structure of the expressed protein corresponding to the only available donkey αs2-CN cDNA sequence was determined. Furthermore β-CN was found in homozygous and heterozygous state for the occurrence of a genetic β-CN variant having a MW value 28 mass units higher than the common β-CN phenotype. 相似文献
986.
Andrea Cappelli Simone Galeazzi Iacopo Zanardi Valter Travagli Maurizio Anzini Raniero Mendichi Stefania Petralito Adriana Memoli Eugenio Paccagnini Walter Peris Antonio Giordani Francesco Makovec Massimo Fresta Salvatore Vomero 《Journal of nanoparticle research》2010,12(3):895-903
Poly-BF3a, a new hydrophobic polymer obtained by spontaneous polymerization of 1-methylene-3-phenyl-1H-indene, was found to give nanoparticles characterized by favorable shape and dimensions. Poly-BF3a nanoparticles were loaded with CR3124, a potent 5HT3 antagonist, as a drug model by desolvation methods either in the absence or in the presence of polyethylene glycol (PEG1000) as a wetting agent. The SEM studies showed that the introduction of CR3124 into the preparation led to a variable degree of aggregation–cementation, which afforded a sort of nanocomposite material. In the absence of PEG1000, the drug molecule was found to stay in the amorphous state (DSC studies) when its percentage is not higher than 10% by weight. In vitro release experiments showed that the formation and stability of the dispersion as well as the drug release were remarkably affected by the presence of PEG1000, demonstrating its beneficial effect to the nanoparticle morphology and disaggregation. 相似文献
987.
Mirco Chiodi Emanuele Cavaliere Iskandar Kholmanov Monica de Simone Oumar Sakho Cinzia Cepek Luca Gavioli 《Journal of nanoparticle research》2010,12(7):2645-2653
We present a morphologic and spectroscopic study of cluster-assembled TiO
x
films deposited by supersonic cluster beam source on clean silicon substrates. Data show the formation of nanometer—thick
and uniform titanium silicides film at room temperature (RT). Formation of such thick TiSi
x
film goes beyond the classical interfacial limit set by the Ti/Si diffusion barrier. The enhancement of Si diffusion through
the TiO
x
film is explained as a direct consequence of the porous film structure. Upon ultra high vacuum annealing beyond 600 °C, TiSi2 is formed and the oxygen present in the film is completely desorbed. The morphology of the nanostructured silicides is very
stable for thermal treatments in the RT—1000 °C range, with a slight cluster size increase, resulting in a film roughness
an order of magnitude smaller than other TiO
x
/Si and Ti/Si films in the same temperature range. The present results might have a broad impact in the development of new
and simple TiSi synthesis methods that favour their integration into nanodevices. 相似文献
988.
Robert V. Harlander Hendrik Mantler Simone Marzani Kemal J. Ozeren 《The European Physical Journal C - Particles and Fields》2010,66(3-4):359-372
The inclusive Higgs production cross section from gluon fusion is calculated through NNLO QCD, including its top quark mass dependence. This is achieved through a matching of the 1/M t expansion of the partonic cross sections to the exact large- $\hat{s}$ limits which are derived from k T -factorization. The accuracy of this procedure is estimated to be better than 1% for the hadronic cross section. The final result is shown to be within 1% of the commonly used effective theory approach, thus confirming earlier findings. 相似文献
989.
J. Daniel Christensen Etera R. Livine Simone Speziale 《Physics letters. [Part B]》2009,670(4-5):403-406
We report on the numerical analysis of the area correlations in spin foam gravity on a single 4-simplex considered by Rovelli [C. Rovelli, Phys. Rev. Lett. 97 (2006) 151301]. We compare the asymptotics and confirm the inverse squared distance leading behaviour at large scales. This supports the recent advances on testing the semiclassical limit of the theory. Furthermore, we show that the microscopic discreteness of the theory dynamically suppresses and regularizes the correlations at the Planck scale. 相似文献
990.
An interacting scalar field with largish coupling to curvature can support a distinctive inflationary universe scenario. Previously this has been discussed for the Standard Model Higgs field, treated classically or in a leading log approximation. Here we investigate the quantum theory using renormalization group methods. In this model the running of both the effective Planck mass and the couplings is important. The cosmological predictions are consistent with existing WMAP5 data, with 0.967?ns?0.98 (for Ne=60) and negligible gravity waves. We find a relationship between the spectral index and the Higgs mass that is sharply varying for mh∼120–135 GeV (depending on the top mass); in the future, that relationship could be tested against data from PLANCK and LHC. We also comment briefly on how similar dynamics might arise in more general settings, and discuss our assumptions from the effective field theory point of view. 相似文献