Measurement of the CP-violation parameter of B-0 mixing and decay with p(p)over-bar ->mu mu X data

We measure the dimuon charge asymmetry A in p (p) over bar collisions at a center of mass energy root s=1960 GeV. The data was recorded with the D0 detector and corresponds to an integrated luminosity of approximately 1.0 fb(-1). Assuming that the asymmetry A is due to asymmetric B-0 <->(B) over bar (0) mixing and decay, we extract the CP-violation parameter of B-0 mixing and decay: ((epsilon B0))/(1+vertical bar epsilon B0 vertical bar 2)=(AB0)/(4)= -0.0023 +/- 0.0011(stat)+/- 0.0008(syst).A(B)(0) is the dimuon charge asymmetry from decays of B-0(B) over bar (0) pairs. The general case, with CP violation in both B-0 and B-s(0) systems, is also considered. Finally we obtain the forward-backward asymmetry that quantifies the tendency of mu(+) to go in the proton direction and mu(-) to go in the antiproton direction. The results are consistent with the standard model and constrain new physics.

Direct limits on the B-s(0) oscillation frequency

We report results of a study of the B-s(0) oscillation frequency using a large sample of B-s(0) semileptonic decays corresponding to approximately 1 fb(-1) of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron Collider in 2002-2006. The amplitude method gives a lower limit on the B-s(0) oscillation frequency at 14.8 ps(-1) at the 95% C.L. At Delta m(s)=19 ps(-1), the amplitude deviates from the hypothesis A=0 (1) by 2.5 (1.6) standard deviations, corresponding to a two-sided C.L. of 1% (10%). A likelihood scan over the oscillation frequency, Delta m(s), gives a most probable value of 19 ps(-1) and a range of 17

Observation of the Doubly Strange b Baryon Omega(-)(b)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Study of direct CP violation in B±→J/ ψK±(π±) decays

We present a search for direct CP violation in B±→J/ ψK±(π±) decays. The event sample is selected from 2.8fb-1 of pp̄ collisions recorded by D0 experiment in run II of the Fermilab Tevatron Collider. The charge asymmetry ACP(B+→J/ψK+)=+0.0075±0. 0061(stat)±0.0030(syst) is obtained using a sample of approximately 40000 B±→J/ψK± decays. The achieved precision is of the same level as the expected deviation predicted by some extensions of the standard model. We also measured the charge asymmetry ACP(B+→J/ψπ+)=-0. 09±0.08(stat)±0.03(syst). © 2008 The American Physical Society.

Chromosomal Mapping of Repetitive DNAs in the Grasshopper Abracris flavolineata Reveal Possible Ancestry of the B Chromosome and H3 Histone Spreading

Supernumerary chromosomes (B chromosomes) occur in approximately 15% of eukaryote species. Although these chromosomes have been extensively studied, knowledge concerning their specific molecular composition is lacking in most cases. The accumulation of repetitive DNAs is one remarkable characteristic of B chromosomes, and the occurrence of distinct types of multigene families, satellite DNAs and some transposable elements have been reported. Here, we describe the organization of repetitive DNAs in the A complement and B chromosome system in the grasshopper species Abracris flavolineata using classical cytogenetic techniques and FISH analysis using probes for five multigene families, telomeric repeats and repetitive C0t-1 DNA fractions. The 18S rRNA and H3 histone multigene families are highly variable and well distributed in A. flavolineata chromosomes, which contrasts with the conservation of U snRNA genes and less variable distribution of 5S rDNA sequences. The H3 histone gene was an extensively distributed with clusters occurring in all chromosomes. Repetitive DNAs were concentrated in C-positive regions, including the pericentromeric region and small chromosomal arms, with some occurrence in C-negative regions, but abundance was low in the B chromosome. Finally, the first demonstration of the U2 snRNA gene in B chromosomes in A. flavolineata may shed light on its possible origin. These results provide new information regarding chromosomal variability for repetitive DNAs in grasshoppers and the specific molecular composition of B chromosomes. © 2013 Bueno et al.

Estrutura molecular e citogenética de cromossomos B em Astyanax paranae (Characiformes, Characidae)

Pós-graduação em Ciências Biológicas (Genética) - IBB

Origin and Evolution of B Chromosomes in the Cichlid Fish Astatotilapia latifasciata Based on Integrated Genomic Analyses

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Observation of the rare B-s(0)->mu(+)mu(-) decay from the combined analysis of CMS and LHCb data

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Does anti-hepatitis B virus vaccine make any difference in long-term number of liver transplantation?

Background: Hepatitis B virus (HBV) infection is a major cause of morbidity and mortality worldwide. Chronic hepatitis B infection is associated with an increased risk of cirrhosis, hepatic decompensation, and hepatocellular carcinoma. Our aim is to analyze, through a mathematical model, the potential impact of anti-HBV vaccine in the long-term (that is, decades after vaccination) number of LT. Methods: The model simulated that the prevalence of HBV infection was 0.5% and that approximately 20% of all the liver transplantation carried out in the state of Sao Paulo are due to HBV infection. Results: The theoretical model suggests that a vaccination program that would cover 80% of the target population would reach a maximum of about 14% reduction in the LT program. Conclusion: Increasing the vaccination coverage against HBV in the state of Sao Paulo would have a relatively low impact on the number of liver transplantation. In addition, this impact would take several decades to materialize due to the long incubation period of liver failure due to HBV.

Relation between Tcc,bb and Xc,b from QCD.

We have studied, using double ratio of QCD (spectral) sum rules, the ratio between the masses of Tcc and X(3872) assuming that they are respectively described by the D−D∗ and D− ¯D∗ molecular currents. We found (within our approximation) that the masses of these two states are almost degenerate. Since the pion exchange interaction between these mesons is exactly the same, we conclude that if the observed X(3872) meson is a D ¯D∗ + c.c. molecule, then the DD∗ molecule should also exist with approximately the same mass. An extension of the analysis to the b-quark case leads to the same conclusion. We also study the SU(3) breakings for the T s Q Q /TQ Q mass ratios. Motivated by the recent Belle observation of two Zb states, we revise our determination of Xb by combining results from exponential and FESR sum rules.

In vivo evaluation in cynomolgus monkey brain and metabolism of [¹⁸F]fluorodeprenyl: a new MAO-B pet radioligand

In this study, we evaluated the in vivo characteristics of a new monoamine oxidase type B (MAO-B) radioligand, [¹⁸F]fluorodeprenyl, by positron emission tomography (PET) in two cynomolgus monkeys. The brain uptake of [¹⁸F]fluorodeprenyl was more than 7% (600% SUV) of the total injected radioactivity and similar to that of [¹¹C]deprenyl, an established MAO-B radioligand. The highest uptake was observed in the striatum, one of the MAO-B-rich regions, with a peak at approximately 2-3 min after injection, followed by lower uptake in the thalamus and the cortex and lowest uptake in the cerebellum. Brain uptake of [¹⁸F]fluorodeprenyl was largely inhibited by preadministration of the MAO-B inhibitor, L-deprenyl, whereas clorgyline, a MAO Type A blocker, had no significant inhibitory effect, thus demonstrating selectivity for MAO-B. [¹⁸F]Fluorodeprenyl showed relatively slow metabolism with the presence of two radiometabolite peaks with similar retention time as the labeled metabolites of [¹¹C]deprenyl. These results suggest that [¹⁸F]fluorodeprenyl is a potential PET radioligand for visualization of MAO-B activity.

Mouse lung CYP1A1 catalyzes the metabolic activation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)

PhIP carcinogenesis is initiated by N(2)-hydroxylation, mediated by several cytochromes P450, including CYP1A1. However, the role of CYP1A1 in PhIP metabolic activation in vivo is unclear. In this study, Cyp1a1-null and wild-type (WT) mice were used to investigate the potential role of CYP1A1 in PhIP metabolic activation in vivo. PhIP N(2)-hydroxylation was actively catalyzed by lung homogenates of WT mice, at a rate of 14.9 +/- 5.0 pmol/min/g tissue, but < 1 pmol/min/g tissue in stomach and small intestine, and almost undetectable in mammary gland and colon. PhIP N(2)-hydroxylation catalyzed by lung homogenates of Cyp1a1-null mice was approximately 10-fold lower than that of WT mice. In contrast, PhIP N(2)-hydroxylation activity in lung homogenates of Cyp1a2-null versus WT mice was not decreased. Pretreatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increased lung Cyp1a1 mRNA and lung homogenate PhIP N(2)-hydroxylase activity approximately 50-fold in WT mice, where the activity was substantially inhibited (70%) by monoclonal antibodies against CYP1A1. In vivo, 30 min after oral treatment with PhIP, PhIP levels in lung were similar to those in liver. After a single dose of 0.1 mg/kg [(14)C]PhIP, lung PhIP-DNA adduct levels in Cyp1a1-null mice, but not in Cyp1a2-null mice, were significantly lower (P=0.0028) than in WT mice. These results reveal that mouse lung has basal and inducible PhIP N(2)-hydroxylase activity predominantly catalyzed by CYP1A1. Because of the high inducibility of human CYP1A1, especially in cigarette smokers, the role of lung CYP1A1 in PhIP carcinogenesis should be considered.

Detection system for Escherichia coli-specific virulence genes: absence of virulence determinants in B and C strains

We describe a rational approach to simultaneously test Escherichia coli strains for the presence of known virulence genes in a reverse dot blot procedure. Specific segments of virulence genes of E. coli designed to have similar hybridization parameters were subcloned on plasmids and subsequently amplified by PCR as unlabeled probes in amounts sufficient to be bound to nylon membranes. Various pathogenic isolates and laboratory strains of E. coli were probed for the presence of virulence genes by labeling the genomic DNA of these strains with digoxigenin and then hybridizing them to the prepared nylon membranes. These hybridization results demonstrated that besides the E. coli K-12 safety strain derivatives, E. coli B and C strains are also devoid of genes encoding any of the investigated virulence factors. In contrast, pathogenic E. coli control strains, used to evaluate the method, showed typical hybridization patterns. The described probes and their easy application on a single filter were shown to provide a useful tool for the safety assessment of E. coli strains to be used as hosts in biotechnological processes. This approach might also be used for the identification and characterization of clinically significant E. coli isolates from human and animal species.

Incidence and Imaging Outcomes of Acute Scaffold Disruption and Late Structural Discontinuity After Implantation of the Absorb Everolimus-Eluting Fully Bioresorbable Vascular Scaffold: Optical Coherence Tomography Assessment in the ABSORB Cohort B Trial (A Clinical Evaluation of the Bioabsorbable Everolimus Eluting Coronary Stent System in the Treatment of Patients With De Novo Native Coronary Artery Lesions).

OBJECTIVES This study sought to describe the frequency and clinical impact of acute scaffold disruption and late strut discontinuity of the second-generation Absorb bioresorbable polymeric vascular scaffolds (Absorb BVS, Abbott Vascular, Santa Clara, California) in the ABSORB (A Clinical Evaluation of the Bioabsorbable Everolimus Eluting Coronary Stent System in the Treatment of Patients With De Novo Native Coronary Artery Lesions) cohort B study by optical coherence tomography (OCT) post-procedure and at 6, 12, 24, and 36 months. BACKGROUND Fully bioresorbable scaffolds are a novel approach to treatment for coronary narrowing that provides transient vessel support with drug delivery capability without the long-term limitations of metallic drug-eluting stents. However, a potential drawback of the bioresorbable scaffold is the potential for disruption of the strut network when overexpanded. Conversely, the structural discontinuity of the polymeric struts at a late stage is a biologically programmed fate of the scaffold during the course of bioresorption. METHODS The ABSORB cohort B trial is a multicenter single-arm trial assessing the safety and performance of the Absorb BVS in the treatment of 101 patients with de novo native coronary artery lesions. The current analysis included 51 patients with 143 OCT pullbacks who underwent OCT at baseline and follow-up. The presence of acute disruption or late discontinuities was diagnosed by the presence on OCT of stacked, overhung struts or isolated intraluminal struts disconnected from the expected circularity of the device. RESULTS Of 51 patients with OCT imaging post-procedure, acute scaffold disruption was observed in 2 patients (3.9%), which could be related to overexpansion of the scaffold at the time of implantation. One patient had a target lesion revascularization that was presumably related to the disruption. Of 49 patients without acute disruption, late discontinuities were observed in 21 patients. There were no major adverse cardiac events associated with this finding except for 1 patient who had a non-ischemia-driven target lesion revascularization. CONCLUSIONS Acute scaffold disruption is a rare iatrogenic phenomenon that has been anecdotally associated with anginal symptoms, whereas late strut discontinuity is observed in approximately 40% of patients and could be viewed as a serendipitous OCT finding of a normal bioresorption process without clinical implications. (ABSORB Clinical Investigation, Cohort B [ABSORB B]; NCT00856856).