3,720 research outputs found
A perturbative probabilistic approach to quantum many-body systems
In the probabilistic approach to quantum many-body systems, the ground-state
energy is the solution of a nonlinear scalar equation written either as a
cumulant expansion or as an expectation with respect to a probability
distribution of the potential and hopping (amplitude and phase) values recorded
during an infinitely lengthy evolution. We introduce a perturbative expansion
of this probability distribution which conserves, at any order, a
multinomial-like structure, typical of uncorrelated systems, but includes,
order by order, the statistical correlations provided by the cumulant
expansion. The proposed perturbative scheme is successfully tested in the case
of pseudo spin 1/2 hard-core boson Hubbard models also when affected by a phase
problem due to an applied magnetic field.Comment: 39 pages, 1 picture, 5 figure
On the possible secondary component of the order parameter observed in London penetration depth measurements
We discuss the effect of a secondary component of the superconducting order
parameter on the superfluid density in the cuprates. If we assume a main
gap, the most stable realization of a mixed order parameter has a
time-reversal breaking symmetry. In this state the
nodes are removed and the temperature dependence of the superfluid density
changes from the linear behavior of a pure d-wave to a more rounded shape at
low temperature. The latter is compatible with the behavior experimentally
observed in the in-plane magnetic field penetration depth of optimally doped
and .Comment: 4 pages, 2 figures, submitted to Phys. Rev.
Prognostic significance of prolactin receptor on overall survival of patients with early breast cancer: a long-term retrospective analysis
Abstract The value of prolactin receptor (PRLR) determination in predicting overall survival has been retrospectively evaluated in a group of 170 women bearing primary breast cancer stage I, II and IIIA. All patients underwent surgery (radical or modified mastectomy or quadrantectomy and axillary dissection followed by radiotherapy according to TNM stage) between January 1977 and December 1986. In all patients, oestrogen and progesterone receptors concentrations were also determined. Overall actuarial survival was higher in patients having PRLR positive tumours when compared to patients having PRLR negative tumours (p = 0.0126). No difference in survival was observed between oestrogen or progesterone receptor positive or negative patients. Using Cox's multivariate analysis on 164 patients, stage and PRLR status were the only significant prognostic factors affecting survival (
Imaging follow-up after liver transplantation
Liver transplantation (LT) represents the best treatment for end-stage chronic liver disease, acute liver failure and early stages of hepatocellular carcinoma. Radiologists should be aware of surgical techniques to distinguish a normal appearance from pathological findings. Imaging modalities, such as ultrasound, CT and MR, provide for rapid and reliable detection of vascular and biliary complications after LT. The role of imaging in the evaluation of rejection and primary graft dysfunction is less defined. This article illustrates the main surgical anastomoses during LT, the normal appearance and complications of the liver parenchyma and vascular and biliary structures.Liver transplantation (LT) represents the best treatment for end-stage chronic liver disease, acute liver failure and early stages of hepatocellular carcinoma. Radiologists should be aware of surgical techniques to distinguish a normal appearance from pathological findings. Imaging modalities, such as ultrasound, CT and MR, provide for rapid and reliable detection of vascular and biliary complications after LT. The role of imaging in the evaluation of rejection and primary graft dysfunction is less defined. This article illustrates the main surgical anastomoses during LT, the normal appearance and complications of the liver parenchyma and vascular and biliary structures
Indentifying sub-network functional modules in protein undirected networks
Protein networks are usually used to describe the interacting behaviours of complex biosystems.
Bioinformatics must be able to provide methods to mine protein undirected networks and to infer subnetworks
of interacting proteins for identifying relevant biological pathways.
Here we present FunMod an innovative Cytoscape version 2.8 plugin able to identify biologically
significant sub-networks within informative protein networks, enabling new opportunities for elucidating
pathways involved in diseases. Moreover FunMod calculates three topological coefficients for each subnetwork,
for a better understanding of the cooperative interactions between proteins and discriminating the
role played by each protein within a functional module.
FunMod is the first Cytoscape plugin with the ability of combining pathways and topological analysis
allowing the identification of the key proteins within sub-network functional modules
Prevalence of Occult Hepatitis B Virus Infection in a Cohort of HIV-Positive Patients Resident in Sicily, Italy
Occult hepatitis B virus (OBI) in HIV-infected groups is still debated, as well as the associated risk-factors and clinical significance. In this paper, we examined a total of 405 HBsAg-negative/HIV-infected patients enrolled from January 2007 to December 2009. Overall, the prevalence of OBI was 5.9% (95% confidence interval (CI95%): 3.8–8.7%); it was more frequently associated with “anti- HBc alone” serological marker (11.3%; adjusted odds ratio = 3.7, CI95%: 1.4–9.8), although it was also detected in the absence of any HBV serological marker (4.9%; CI95%: 2.3–9.1%). A low prevalence of anti-HCV-positive patients with OBI was found (3.1%; CI95%: 0.6–8.7%). HIV RNA plasma levels or other immunological/clinical characteristics were not significantly associated with OBI. All but one occult HBV infections were sustained by genotype D viral strains. OBI is relatively frequent in HIV-infected patients, although it does not seem to exert a relevant clinical impact. Viral genotypes in occult HBV infections reflect those circulating in the Mediterranean area
Subtyping patients with somatic tinnitus: modulation of tinnitus and history for somatic dysfunction help identify tinnitus patients with temporomandibular joint disorders
Objective: Determine in a cohort of patients with normal hearing and chronic tinnitus if self-reported history for temporomandibular joint (TMJ) dysfunction and a positive modulation of tinnitus in the TMJ region could be suggestive of an underlying TMJ disorder. Patients and Methods: The study included 226 patients presenting to the Head and Neck Service of our University Hospital. Following audiological and somatic tinnitus evaluation, patients were divided into two groups. The study group (n= 134) included subjects that met both the following criteria: A) a self-reported history for TMJ dysfunction and B) a positive modulation of tinnitus following somatic maneuvers in the TMJ region. The control group (n=92) included patients with similar demographic and tinnitus characteristics that did not meet the proposed criteria for somatic tinnitus. Afterwards, patients underwent clinical TMJ evaluation in the Service of Clinical Gnathology of our University. Results: One hundred thirty-one patients (57.9%) received a clinical diagnosis of TMJ disorder according to DC/TMD Axis I; 79.1% in the study group and 27.2% in the control group. Ninety-five (42.1%) patients were negative for TMJ disorders; 20.9% in the study group and 72.8% in the control group. A significantly higher number of TMJ disorders was found in patients in the study group compared to the control group (p<0.0001). Most patients had joint disorders (67.2%), followed by other (29.8%) and pain disorders (29%). Logistic regression analysis in the study group showed that female gender was more prevalent in patients with TMJ disorders. Conclusion: Our findings in patients with chronic tinnitus and normal hearing suggest that self-reported history for somatic dysfunction and modulation of tinnitus, when occurring simultaneously in the TMJ region, can be useful to preliminarily identify patients with TMJ disorders
CD3+CD4+LAP+Foxp3-regulatory cells of the colonic lamina propria limit disease extension in ulcerative colitis
Background and Aims: In ulcerative colitis (UC), inflammation begins in the rectum and
can extend proximally throughout the entire colon. The extension of inflammation is an
important determinant of disease course, and may be limited by the action of regulatory
T cells (Tregs). In this cross-sectional study, we evaluated the relationship between UC
extension and the proportions of CD3+CD4+Foxp3+ and CD3+CD4+LAP+Foxp3-
Tregs in the colonic lamina propria (LP) of 79 UC patients and 29 controls. The role of
these cells in UC extension was also investigated in the murine oxazolone-induced colitis
model.
Methods: Patients: Disease extension was classified according to the Montreal
classification. Where possible, endoscopic biopsies of involved and uninvolved
tissue were obtained from UC patients. Mouse model: Colitis was induced by
intrarectal oxazolone administration. Lamina propria mononuclear cells were isolated
from patient biopsies and mouse colon tissue using enzymatic method and the
percentage of CD3+CD4+Foxp3+ and CD3+CD4+LAP+Foxp3-cells evaluated by
immunofluorescence. Confocal microscopy was applied for the visualization and
quantification of CD4+LAP+ cells on tissue histological sections.
Results: In UC patients with distal colitis the proportion of LP CD3+CD4+Foxp3+
Tregs was significantly higher in inflamed tissue than uninvolved tissue. As opposite, the
proportion of LP CD3+CD4+LAP+ Tregs was significantly higher in uninvolved tissue
than involved tissue. Both LP CD3+CD4+Foxp3+ and LP CD3+CD4+LAP+ Tregs
proportion in involved tissue was significantly higher than in controls irrespective of the
extension of inflammation. In mice with oxazolone-induced distal colitis, treatment with
LAP-depleting antibody was associated with the development of extensive colitis.
Conclusions: Our findings suggest that CD3+CD4+LAP+Foxp3-Tregs limit the
extension of inflammatory lesions in UC patients
Stable Oxidative Cytosine Modifications Accumulate in Cardiac Mesenchymal Cells from Type2 Diabetes Patients: Rescue by alpha Ketoglutarate and TET-TDG Functional Reactivation
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