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21.
Donato Bini Christian Cherubini Marco de Mattia Robert T. Jantzen 《General Relativity and Gravitation》2003,35(12):2249-2260
Accelerated circular orbits in the equatorial plane of the Taub-NUT spacetime are analyzed to investigate the effects of its gravitomagnetic monopole source. The effect of a small gravitomagnetic monopole on these orbits is compared to the corresponding orbits pushed slightly off the equatorial plane in the absence of the monopole. 相似文献
22.
David A. M. C. van de Vijver Mattia C. F. Prosperi José J. Ramasco 《The European physical journal. Special topics》2013,222(6):1403-1411
We are reviewing the literature regarding sexual networks and HIV transmission in sub-Saharan Africa and Europe. On Likoma Island in Malawi, a sexual network was reconstructed using a sociometric survey in which individuals named their sexual partners. The sexual network identified one giant component including half of all sexually active individuals. More than 25% of respondents were linked through independent chains of sexual relations. HIV was more common in the sparser regions of the network due to over-representation of groups with higher HIV prevalence. A study from KwaZulu-Natal in South-Africa collected egocentric data about sexual partners and found that new infections in women in a particular area was associated with the number of life-time partners in men. Data about sexual networks and HIV transmission are not reported in Europe. It is, however, found that the annual number of sexual partners follows a scale-free network. Phylogenetic studies that determine genetic relatedness between HIV isolates obtained from infected individuals, found that patients in the early stages of infections explain a high number of new infections. In conclusion, the limited information that is available suggest that sexual networks play a role in spread of HIV. Obtaining more information about sexual networks can be of benefit for modeling studies on HIV transmission and prevention. 相似文献
23.
Rendiconti del Circolo Matematico di Palermo Series 1 - 相似文献
24.
Antonella De Palma Antonella Roveri Mattia Zaccarin Louise Benazzi Simone Daminelli Giorgia Pantano Mauro Buttarello Fulvio Ursini Massimo Gion Pier Luigi Mauri 《Journal of chromatography. A》2010,1217(33):5328-5336
Since red blood cells (RBCs) lack nuclei and organelles, cell membrane is their main load-bearing component and, according to a dynamic interaction with the cytoskeleton compartment, plays a pivotal role in their functioning. Even if erythrocyte membranes are available in large quantities, the low abundance and the hydrophobic nature of cell membrane proteins complicate their purification and detection by conventional 2D gel-based proteomic approaches. So, in order to increase the efficiency of RBC membrane proteome identification, here we took advantage of a simple and reproducible membrane sub-fractionation method coupled to Multidimensional Protein Identification Technology (MudPIT). In addition, the adoption of a stringent RBC filtration strategy from the whole blood, permitted to remove exhaustively contaminants, such as platelets and white blood cells, and to identify a total of 275 proteins in the three RBC membrane fractions collected and analysed. Finally, by means of software for the elaboration of the great quantity of data obtained and programs for statistical analysis and protein classification, it was possible to determine the validity of the entire system workflow and to assign the proper sub-cellular localization and function for the greatest number of the identified proteins. 相似文献
25.
We study the dynamics of a noisy network of spiking neurons with spike-frequency adaptation (SFA), using a mean-field approach, in terms of a two-dimensional Fokker-Planck equation for the membrane potential of the neurons and the calcium concentration gating SFA. The long time scales of SFA allow us to use an adiabatic approximation and to describe the network as an effective nonlinear two-dimensional system. The phase diagram is computed for varying levels of SFA and synaptic coupling. Two different population-bursting regimes emerge, depending on the level of SFA in networks with noisy emission rate, due to the finite number of neurons. 相似文献
26.
Falconi M Oteri F Di Palma F Pandey S Battistoni A Desideri A 《Journal of computer-aided molecular design》2011,25(2):181-194
Comparative homology modelling techniques have been used to model the protein ZnuA from Salmonella enterica serovar Typhimurium using the 3D structure of the homologous protein from Escherichia coli. These two-domain proteins bind one Zn2+ atom, with high affinity, in the inter-domain cleft and possess a histidine-rich loop in the N-terminal domain. Alternative
structures of the ZnuA histidine-rich loop, never resolved by the X-ray diffraction method, have been modelled. A model of
the apo form, one with the histidine-rich loop deleted and two alternative structures with a second zinc ion bound to the
histidine-rich loop, have been generated. In all the modelled proteins, investigated through molecular dynamics simulation,
the histidine-rich loop is highly mobile and its fluctuations are correlated to the ligand stability observed in the zinc
sites. Based on the plasticity of the histidine-rich loop and its significant effects on protein mobility a possible role
in the capture and/or transfer of the zinc ions has been suggested. 相似文献
27.
Di Santo G Blankenburg S Castellarin-Cudia C Fanetti M Borghetti P Sangaletti L Floreano L Verdini A Magnano E Bondino F Pignedoli CA Nguyen MT Gaspari R Passerone D Goldoni A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(51):14354-14359
Scratching the surface: Formation of a monolayer of 2H-tetraphenylporphyrins (2H-TPP) on Ag(111), either by sublimation of a multilayer in the range 525-600?K or by annealing (at the same temperature) a monolayer deposited at room temperature, induces a chemical modification of the molecules. Rotation of the phenyl rings into a flat conformation is observed and tentatively explained, by using DFT calculations, as a peculiar reaction due to molecular dehydrogenation. 相似文献
28.
Luigi Fortuna Mattia Frasca Salvatore Graziani Salvatore Reddiconto 《Nonlinear dynamics》2006,44(1-4):55-61
In this paper, the possibility of observing strange attractors in an electronic circuit including a nonlinear ferroelectric
component has been investigated. The ferroelectric constitutes the medium interposed between the two plates of a capacitor.
A circuit including the nonlinearity of the ferroelectric has been designed, while the parameters have been found by performing
numerical integration with respect to different values of them. The circuit has been realized on a discrete components board.
Experimental results, showing that for a suitable range of parameters a chaotic attractor emerges, are reported. 相似文献
29.
30.
C. A. Mattia L. Mazzarella V. Vitagliano R. Puliti 《Journal of chemical crystallography》1984,14(1):71-87
The crystal structure of acridine orange hydroiodide and that of acridine orange hydrochloride monohydrate have been solved by X-ray diffraction analysis. The absorption spectra of both derivatives in the solid state have also been reported and compared with those of the acridinium ion in solution. The stacking interactions of the acridine orange molecule in both derivatives is discussed in the light of the visible absorption spectra in the solid state and in solution. 相似文献