A simple topological model with continuous phase transition

In the area of topological and geometric treatment of phase transitions and symmetry breaking in Hamiltonian systems, in a recent paper some general sufficient conditions for these phenomena in $\mathbb{Z}_2$-symmetric systems (i.e. invariant under reflection of coordinates) have been found out. In this paper we present a simple topological model satisfying the above conditions hoping to enlighten the mechanism which causes this phenomenon in more general physical models. The symmetry breaking is testified by a continuous magnetization with a nonanalytic point in correspondence of a critical temperature which divides the broken symmetry phase from the unbroken one. A particularity with respect to the common pictures of a phase transition is that the nonanalyticity of the magnetization is not accompanied by a nonanalytic behavior of the free energy.Comment: 17 pages, 7 figure

Topological conditions for discrete symmetry breaking and phase transitions

In the framework of a recently proposed topological approach to phase transitions, some sufficient conditions ensuring the presence of the spontaneous breaking of a Z_2 symmetry and of a symmetry-breaking phase transition are introduced and discussed. A very simple model, which we refer to as the hypercubic model, is introduced and solved. The main purpose of this model is that of illustrating the content of the sufficient conditions, but it is interesting also in itself due to its simplicity. Then some mean-field models already known in the literature are discussed in the light of the sufficient conditions introduced here

Pegylated interferon α plus ribavirin for the treatment of chronic hepatitis C: A multicentre independent study supported by the Italian Drug Agency

168nononeBackground: Data on the efficacy of Peg-interferon/ribavirin therapy for chronic hepatitis C are mostly derived from treatment of selected patients enrolled in clinical trials. This study aimed to assess the effectiveness of Peg-interferon/ribavirin therapy in "real world" chronic hepatitis C patients in Italy. Methods: Independent observational multicentre study including consecutive patients receiving Peg-interferon/ribavirin in the 18 months before (retrospective phase) and after (prospective phase) the start of the study. Results: 4176 patients were eligible. The final study population consisted of 2051 patients in the retrospective and 2073 in the prospective phase.Sustained virological response was achieved by 1036 patients (50.5%) during the retrospective phase: 325 were genotypes 1/4 (34.1%) and 684 were genotypes 2/3 (67.2%) and by 800 patients (38.6%) during the prospective phase: 300 were genotypes 1/4 (28.4%) and 473 were genotypes 2/3 (51.5%).During multivariate analysis genotypes 2/3 were significantly associated with higher sustained virological response rates; cirrhosis and γ-glutamil-transpeptidase >2 times the normal limit were associated with poorer response. Conclusions: The response to Peg-interferon/ribavirin therapy in "real world" clinical practice is distinctly lower than in registration trials. The difference in response rates was more pronounced among easy-to-treat than among difficult-to-treat hepatitis C virus genotypes. © 2014 Editrice Gastroenterologica Italiana S.r.l.Rosina, Floriano; Tosti, Maria Elena; Borghesio, Elisabetta; Masocco, Maria; Mele, Alfonso; Coppola, Carmine; Milella, Michele; Borgia, Guglielmo; Andreone, Pietro; Koch, Maurizio; Zignego, Anna Linda; Romano, Mario; Carrara, Maurizio; Almasio, Piero Luigi; Azzola, Emilio; Nardone, Gerardo; Benedetti, Antonio; Carosi, Giampiero; Mazzotta, Francesco; Sagnelli, Evangelista; Rizzetto, Mario; Mascolo, M.C.; Cursaro, C.; Scuteri, A.; Crespi, C.; Gianstefani, A.; Ranieri, J.; Monti, M.; Corti, G.; Blanc, P.L.; Baragli, F.; Bellentani, S.; Gasbarrini, A.; Pompili, M.; Mecenate, F.; Picardi, A.; Vespasiani, U.; Nosotti, Null; Gasbarrini, A.; Pompili, M.; Mecenate, F.; Null, A.Picardi; Nosotti, Null; Ricci, G.L.; Paffetti, A.; Mastropietro, C.; Moretti, A.; Spagnolo, A.L.; Puoti, C.; Bellis, L.; Regazzetti, A.; Maffezzini, E.; Pietrangelo, A.; Abbati, G.; Borghi, A.; Sardini, C.; Raimondo, G.; Scribano, L.; Martines, D.; Svegliati Baroni, G.; Faraci, G.; Schi-anchi, S.; Fornaciari, G.; Massari, M.; Fabris, P.; Bertin, T.; Salvagnini, M.; Madonia, S.; Calì, A.; Civitavecchia, G.; Pirisi, M.; Smirne, C.; Andreoletti, M.; Morisco, F.; Caporaso, N.; Gentile, I.; Brancaccio, G.; Gaeta, G.B.; Liberti, A.; Iannece, M.D.; Rocco, A.; Federico, A.; Loguercio, C.; Riegler, G.; Esposito, P.; Fargion, S.; Fatta, E.; Masutti, F.; Bonaventura, M.E.; Autolitano, A.; Russello, M.; Bellia, A.; Toniutto, P.; Bitetto, D.; Pasulo, L.; Lucà, M.G.; Grattagliano, I.; Palasciano, G.; Romagno, D.; Giannelli, G.; Napoli, N.; Plattella, M.S.; Cassano, P.; Gobbo, G.; Monti, V.; Raspanti, A.; Cuccorese, Null; Colombo, A.E.; Mandelli, G.; Spinzi, G.C.; Floridia, Null; Messina, V.; Bonfante, S.; Bellissima, P.; Toti, M.; Vecchiet, J.; Falasca, K.; Portelli, V.; Stefano, G. De; Pietromatera, G.; Viganò, P.; Re, T.; Andreoni, M.; Null, G.Raineri; Grossi, P.A.; Caputo, S.; Cassola, G.; Feasi, M.; Biagio, A. Di; Nicolini, L.; Giannini, E.G.; Corbo, M.; Foti, G.; Kunkar, A.; Caterini, L.; Migliorini, D.; Chiodera, A.; Calleri, G.; Spezia, C.; Framarin, L.; Null, M.Berrutti; Ciancio, A.; Baiguera, C.; Puoti, M.; Vento, S.; Contini, C.; Boccia, S.; Casiraghi, M.A.; Simone, L.; Tacconi, D.; Caremani, M.; Almi, P.; Chimenti, M.; Cosco, Null; Messeri, D.; Esperti, F.C.; Lomonaco, L.; Pazzi, P.; Fornari, F.; Comparato, G.; Casetti, T.; Foschi, F.G.; Samori, A.; Ferretti, E.; Marin, R.; Campo, N.; Testa, R.; Rizzo, S.Rosina, Floriano; Tosti, Maria Elena; Borghesio, Elisabetta; Masocco, Maria; Mele, Alfonso; Coppola, Carmine; Milella, Michele; Borgia, Guglielmo; Andreone, Pietro; Koch, Maurizio; Zignego, Anna Linda; Romano, Mario; Carrara, Maurizio; Almasio, Piero Luigi; Azzola, Emilio; Nardone, Gerardo; Benedetti, Antonio; Carosi, Giampiero; Mazzotta, Francesco; Sagnelli, Evangelista; Rizzetto, Mario; Mascolo, M. C.; Cursaro, C.; Scuteri, A.; Crespi, C.; Gianstefani, A.; Ranieri, J.; Monti, M.; Corti, G.; Blanc, P. L.; Baragli, F.; Bellentani, S.; Gasbarrini, A.; Pompili, M.; Mecenate, F.; Picardi, A.; Vespasiani, U.; Nosotti, Null; Gasbarrini, A.; Pompili, M.; Mecenate, F.; Null, A. Picardi; Nosotti, Null; Ricci, G. L.; Paffetti, A.; Mastropietro, C.; Moretti, A.; Spagnolo, A. L.; Puoti, C.; Bellis, L.; Regazzetti, A.; Maffezzini, E.; Pietrangelo, A.; Abbati, G.; Borghi, A.; Sardini, C.; Raimondo, G.; Scribano, L.; Martines, D.; Svegliati Baroni, G.; Faraci, G.; Schi anchi, S.; Fornaciari, G.; Massari, M.; Fabris, P.; Bertin, T.; Salvagnini, M.; Madonia, S.; Calì, A.; Civitavecchia, G.; Pirisi, M.; Smirne, C.; Andreoletti, M.; Morisco, F.; Caporaso, N.; Gentile, I.; Brancaccio, G.; Gaeta, G. B.; Liberti, A.; Iannece, M. D.; Rocco, A.; Federico, A.; Loguercio, C.; Riegler, G.; Esposito, P.; Fargion, S.; Fatta, E.; Masutti, F.; Bonaventura, M. E.; Autolitano, A.; Russello, M.; Bellia, A.; Toniutto, P.; Bitetto, D.; Pasulo, L.; Lucà, M. G.; Grattagliano, I.; Palasciano, G.; Romagno, D.; Giannelli, G.; Napoli, N.; Plattella, M. S.; Cassano, P.; Gobbo, G.; Monti, V.; Raspanti, A.; Cuccorese, Null; Colombo, A. E.; Mandelli, G.; Spinzi, G. C.; Floridia, Null; Messina, V.; Bonfante, S.; Bellissima, P.; Toti, M.; Vecchiet, J.; Falasca, K.; Portelli, V.; Stefano, G. De; Pietromatera, G.; Viganò, P.; Re, T.; Andreoni, M.; Null, G. Raineri; Grossi, PAOLO ANTONIO; Caputo, S.; Cassola, G.; Feasi, M.; Biagio, A. Di; Nicolini, L.; Giannini, E. G.; Corbo, M.; Foti, G.; Kunkar, A.; Caterini, L.; Migliorini, D.; Chiodera, A.; Calleri, G.; Spezia, C.; Framarin, L.; Null, M. Berrutti; Ciancio, A.; Baiguera, C.; Puoti, M.; Vento, S.; Contini, C.; Boccia, S.; Casiraghi, M. A.; Simone, L.; Tacconi, D.; Caremani, M.; Almi, P.; Chimenti, M.; Cosco, Null; Messeri, D.; Esperti, F. C.; Lomonaco, L.; Pazzi, P.; Fornari, F.; Comparato, G.; Casetti, T.; Foschi, F. G.; Samori, A.; Ferretti, E.; Marin, R.; Campo, N.; Testa, R.; Rizzo, S

Pegylated interferon α plus ribavirin for the treatment of chronic hepatitis C: a multicentre independent study supported by the Italian Drug Agency

BACKGROUND: Data on the efficacy of Peg-interferon/ribavirin therapy for chronic hepatitis C are mostly derived from treatment of selected patients enrolled in clinical trials. This study aimed to assess the effectiveness of Peg-interferon/ribavirin therapy in "real world" chronic hepatitis C patients in Italy. METHODS: Independent observational multicentre study including consecutive patients receiving Peg-interferon/ribavirin in the 18 months before (retrospective phase) and after (prospective phase) the start of the study. RESULTS: 4176 patients were eligible. The final study population consisted of 2051 patients in the retrospective and 2073 in the prospective phase. Sustained virological response was achieved by 1036 patients (50.5%) during the retrospective phase: 325 were genotypes 1/4 (34.1%) and 684 were genotypes 2/3 (67.2%) and by 800 patients (38.6%) during the prospective phase: 300 were genotypes 1/4 (28.4%) and 473 were genotypes 2/3 (51.5%). During multivariate analysis genotypes 2/3 were significantly associated with higher sustained virological response rates; cirrhosis and γ-glutamil-transpeptidase >2 times the normal limit were associated with poorer response. CONCLUSIONS: The response to Peg-interferon/ribavirin therapy in "real world" clinical practice is distinctly lower than in registration trials. The difference in response rates was more pronounced among easy-to-treat than among difficult-to-treat hepatitis C virus genotype

Pegylated interferon α plus ribavirin for the treatment of chronic hepatitis C: A multicentre independent study supported by the Italian Drug Agency

Background: Data on the efficacy of Peg-interferon/ribavirin therapy for chronic hepatitis C are mostly derived from treatment of selected patients enrolled in clinical trials. This study aimed to assess the effectiveness of Peg-interferon/ribavirin therapy in "real world" chronic hepatitis C patients in Italy. Methods: Independent observational multicentre study including consecutive patients receiving Peg-interferon/ribavirin in the 18 months before (retrospective phase) and after (prospective phase) the start of the study. Results: 4176 patients were eligible. The final study population consisted of 2051 patients in the retrospective and 2073 in the prospective phase.Sustained virological response was achieved by 1036 patients (50.5%) during the retrospective phase: 325 were genotypes 1/4 (34.1%) and 684 were genotypes 2/3 (67.2%) and by 800 patients (38.6%) during the prospective phase: 300 were genotypes 1/4 (28.4%) and 473 were genotypes 2/3 (51.5%).During multivariate analysis genotypes 2/3 were significantly associated with higher sustained virological response rates; cirrhosis and γ-glutamil-transpeptidase >2 times the normal limit were associated with poorer response. Conclusions: The response to Peg-interferon/ribavirin therapy in "real world" clinical practice is distinctly lower than in registration trials. The difference in response rates was more pronounced among easy-to-treat than among difficult-to-treat hepatitis C virus genotypes. © 2014 Editrice Gastroenterologica Italiana S.r.l