Magnetic structures of quaternary intermetallic borocarbides RCo(2)B(2)C (R = Dy, Ho, Er)

The magnetic structures of the title compounds have been studied by neutron diffraction. In contrast to the isomorphous RNi(2)B(2)C compounds, wherein a variety of exotic incommensurate modulated structures has been observed, the magnetic structure of ErCo(2)B(2)C is found to be a collinear antiferromagnet with k = (12, 0, 12) while those of HoCo(2)B(2)C and DyCo(2)B(2)C are observed to be simple ferromagnets. For all studied compounds, the moments are found to be confined within the basal plane and their magnitudes are comparable to the values obtained from the low-temperature isothermal magnetization measurements. The absence of modulated magnetic structures in the RCo(2)B(2)C series (for ErCo(2)B(2)C, verified down to 50 mK) is attributed to the quenching of the Fermi surface nesting features.

Synthesis and magnetic characterization of TmCo(2)B(2)C

A new quaternary intermetallic borocarbide TmCo(2)B(2)C has been synthesized via rapid-quench of an arc-melted ingot. Elemental and powder-diffraction analyses established its correct stoichiometry and single-phase character. The crystal structure is isomorphous with that of TmNi(2)B(2)C (I4/mmm) and is stable over the studied temperature range. Above 7 K, the paramagnetic state follows modified Curie-Weiss behavior (chi = C/(T - theta) + chi(0)) wherein chi(0) = 0.008(1) emu mol(-1) with the temperature-dependent term reflecting the paramagnetism of the Tm subsystem: mu(eff) = 7.6(2) mu(B) (in agreement with the expected value for a free Tm(3+) ion) and theta = -4.5(3) K. Long-range ferromagnetic order of the Tm sublattice is observed to develop around similar to 1 K. No superconductivity is detected in TmCo(2)B(2)C down to 20 mK, a feature which is consistent with the general trend in the RCo(2)B(2)C series. Finally, the influence of the rapid-quench process on the magnetism (and superconductivity) of TmNi(2)B(2)C will be discussed and compared to that of TmCo(2)B(2)C.

Prevalence of hepatitis B and C serological markers among first-time blood donors in Brazil: A multi-center serosurvey

Little data are available on the seroprevalence of, and risk factors for hepatitis B and C viruses (HBV and HCV) infection in Latin American countries. A multi-center serosurvey was conducted among 3,598 first-time blood donors (65% men) from Sao Paulo, Salvador and Manaus in Brazil. The gender-specific seroprevalences of antibodies against hepatitis B core antigen (anti-HBc) and of the hepatitis B surface antigen (HBsAg) in anti-HBc-positive sera were measured, and risk factors analyzed by gender. The gender-specific seroprevalences of antibodies against HCV (anti-HCV) were measured, but risk factors for HCV were not determined. Anti-HBc and HBsAg seroprevalences were not significantly different in men [101/2,341 (4.31%) and 4/2,229 (0.18%), respectively] and women [65/1,237 (5.25%) and 8/ 1,169 (0.68%), respectively], whereas the seroprevalence of anti-HCV was higher in women (12/1,238 [0.97%] vs. 9/2,353 [0.38%]; odds ratio [OR] = 2.49; 95% confidence interval [Cl]: 1.0-6.0). No significant difference for HBV infection was found across the three study sites or by ethnic group. The seroprevalence of anti-HBc increased with age, but decreased with education level in both genders. Lifetime number of sexual partners was associated with anti-HBc prevalence among men (OR = 1.95; 95% Cl: 1.2-3.1), but not women. The seroprevalence of HBV and HCV was low among Brazilian blood donors, and exposure increased with age in both genders.

Qu est-ce que c est?: uma HQ autobiográfica de Fábio Moon e Gabriel Bá.

Partindo da ideia de que as histórias em quadrinhos, apesar de serem consideradas um gênero híbrido, possuem também uma linguagem autônoma, este trabalho busca investigar por meio de análise de conteúdo uma história em quadrinhos (HQ)autobiográfica dos gêmeos paulistas Fábio Moon e Gabriel Bá, Qu’est-ce que c’est?, publicada pela primeira vez em inglês na coletânea Autobiographix (Dark Horse Books, 2003) e republicada em português no livro Crítica (Devir, 2004). Serão analisados recursos estéticos e narrativos, tentando descobrir também quais são as particularidades de uma HQ autobiográfica. A história narra a saga dos irmãos durante uma viagem a Paris, onde foram visitar museus e colher referências para seu trabalho. No metrô, eles se depararam com uma gangue da periferia.

On (b,c)-system at finite temperature in thermo field approach

We construct the finite temperature field theory of the two-dimensional ghost-antighost system within the framework of thermo field theory. (C) 2000 Elsevier B.V. B.V. All rights reserved.

Measurement of the Lifetime of the B-c(+/-) Meson in the Semileptonic Decay Channel

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

Morfoanatomia e ontogênese das sementes de espécies de Banisteriopsis C.B. Robinson e Diplopterys A. Juss. (Malpighiaceae)

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

Whole-body protein turnover in malnourished patients with child class B and C cirrhosis on diets low to high in protein energy

The purpose of this study was to determine the rate of whole-body protein turnover in moderately and severely alcoholic, malnourished, cirrhotic patients fed with different amounts of protein or energy. Six male patients (Child classes B and C) and four age- and sex-matched healthy control subjects were studied for 18 d in fasting and feeding states; a single oral dose of [N-15]glycine was used as a tracer and urinary ammonia was the end product. The kinetic study showed that patients had higher protein catabolism while fasting (patients: 3.14 +/- 1.2 g of lean body mass/9 h; controls: 1.8 +/- 0.3 g of lean body mass/9 h: P<0.02). Although not statistically significant, protein catabolism (grams of lean body mass/9 h) was lower with the hyperproreic/hyperenergetic diet when compared with fasting. Nitrogen retention was consistent with the lower protein-catabolism rate; a statistically significant increase in nitrogen balance was observed when patients were fed with the hyperproteic/hyperenergetic diet compared with fasting 14.3 +/- 3.2 g of nitrogen/d and -2.2 +/- 1.9 g of nitrogen/d, respectively; P < 0.01). These data indicate that Child class B and C cirrhotic patients are hypercatabolic and that Long-term nutritional intervention with a hyperproteic/hyperenergetic diet is likely needed to improve their clinical and nutritional status. Nutrition 2001;17:239-242. (C) Elsevier B.V. 2001.

A SUGGESTION ON THE PAIR OF QSO TRIPLETS 1130+106 (B,A,C), (X,Y,Z)

The alignment of a pair of QSO triplets discovered by Arp and Hazard are tentatively explained by a combination of (I) the idea of quasar ejection by galaxies; (II) a construction by Narlikar suggesting a common origin for the six images; and (III) a nontrivial topology of cosmic space.

Serologic profile in hepatitis B virus and hepatitis C virus in a Brazilian liver transplant waiting list

Chronic viral hepatitis is currently the most common indication for liver transplantation (OLT). Knowing the serological profile of patients on the liver transplant waiting list (LTWL) is essential to manage prophylactic and therapeutic strategies pre- and post-OLT. The aim of this study was to determine the hepatitis B virus (HBV) and hepatitis C virus (HCV) serological profile on the LTWL.Methods. Serological data were collected from 44 candidates included on, the LTWL from May 2003 to November 2004. HBV and HCV serological profiles were performed by microenzyme immunoassay.Results. Twenty-eight patients (66.7%) lacked H13V serological markers. Anti-HBs was detected in 9.5% and was positive for HBsAg, anti-HBc, IgM anti-HBc, or HbeAg in 4.8% of patients, probably related to reactivation of chronic infection. In 7.1% of patients, the markers demonstrated serological cure of infection. In HCV patients, 41.5% were positive. There was H13V and HCV co-infection in 12.2% of patients.Conclusion. HBV infection in 21.4% of the patients corroborates the need to use more efficient protocols for prophylactic and therapeutic management pre- and post-OLT. The high prevalence of HCV infection reinforces the need to follow adequate protocols to avoid related complications and guarantee rational and universal use of more efficient drugs.

Short communication longitudinal variation in the concentrations of C, N and P in the stem of Echinochloa polystachya (H.B.K.) Hitchcock

The Concentrations of C, N and P were determined in the internodes of the stem of Echinochloa polystachya (H.B.K.) Hitchcock with the aim of showing their longitudinal distributions. The concentrations ranged from 421.93 to 466.03 mgCgDW-1; from 2.78 to 13.61 mg N gDW-1 and from 0.151 to 1.074 mg P gDW-1. N and P concentrations increased towards the apical direction of the stem. C concentrations showed an inverse trend. These distributions suggest that N and P are transported to the apical region of the stem, while the majority of the C compounds observed in the distal region must be retained in the supporting structure of the plant.

Temporal variation in C, N and P of the periphyton on the tropical aquatic macrophyte echinochloa polystachya (H.B.K.) hitch. In Jurumirim Reservoir (São Paulo, Brazil)

The temporal variations in C, N and P concentrations of the periphyton on the natural substratum (Echinochloa polystachya) and its relationships to the water's climatological (air temperature and precipitation), hydrodynamic (water discharge and water level), physical (temperature, transparency) and chemical variables (conductivity, total suspended solids, nitrate, nitrite, ammonia, silica, total phosphorus and orthophosphate) were evaluated in a lagoon at the Paranapanema River mouth into the Jurumirim Reservoir (São Paulo, Brazil) from August 1993 to July 1994. An amplitude variation of 2.0 m in water level was observed. Depending on to the hydrologic conditions, the lagoon presents intermediate conditions of lentic and lotic environments. The amplitude variations in C, N and P were 14.5-52.1% C DW-1, 0.5-3.2% N DW-1, and 0.03-0.4% P DW-1, respectively. The periphyton presented a decreased protein content. The environmental trophic degree appears to be decisive in chemical periphyton composition.

Influência do vírus da hepatite B na infecção crônica pelo vírus da hepatite C: perfil das séricas e histopatologia hepática

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)