Thermal conductivity as influenced by the temperature and apparent viscosity of dairy products.

This study aimed to evaluate the rheological behavior and thermal conductivity of dairy products, composed of the same chemical components but with different formulations, as a function of temperature. Subsequently, thermal conductivity was related to the apparent viscosity of yogurt, fermented dairy beverage, and fermented milk. Thermal conductivity measures and rheological tests were performed at 5, 10, 15, 20, and 25°C using linear probe heating and an oscillatory rheometer with concentric cylinder geometry, respectively. The results were compared with those calculated using the parallel, series, and Maxwell-Eucken models as a function of temperature, and the discrepancies in the results are discussed. Linear equations were fitted to evaluate the influence of temperature on the thermal conductivity of the dairy products. The rheological behavior, specifically apparent viscosity versus shear rate, was influenced by temperature. Herschel-Bulkley, power law, and Newton's law models were used to fit the experimental data. The Herschel-Bulkley model best described the adjustments for yogurt, the power law model did so for fermented dairy beverages, and Newton's law model did so for fermented milk and was then used to determine the rheological parameters. Fermented milk showed a Newtonian trend, whereas yogurt and fermented dairy beverage were shear thinning. Apparent viscosity was correlated with temperature by the Arrhenius equation. The formulation influenced the effective thermal conductivity. The relationship between the 2 properties was established by fixing the temperature and expressing conductivity as a function of apparent viscosity. Thermal conductivity increased with viscosity and decreased with increasing temperature.

A Dual-Colour Architecture for Pump-Probe Spectroscopy of Ultrafast Magnetization Dynamics in the Sub-10-femtosecond Range.

Current time-resolution-limited dynamic measurements clearly show the need for improved techniques to access processes on the sub-10-femtosecond timescale. To access this regime, we have designed and constructed a state-of-the-art time-resolved magneto-optic Kerr effect apparatus, based on a new dual-color scheme, for the measurement of ultrafast demagnetization and precessional dynamics in magnetic materials. This system can operate well below the current temporal ranges reported in the literature, which typically lie in the region of around 50 fs and above. We have used a dual-colour scheme, based on ultra broadband hollow-core fibre and chirped mirror pulse compression techniques, to obtain unprecedented sub-8-fs pump and probe pulse durations at the sample plane. To demonstrate the capabilities of this system for ultrafast demagnetization and precessional dynamics studies, we have performed measurements in a ferrimagnetic GdFeCo thin film. Our study has shown that the magnetization shows a sudden drop within the first picosecond after the pump pulse, a fast recovery (remagnetization) within a few picoseconds, followed by a clear oscillation or precession during a slower magnetization recovery. Moreover, we have experimentally confirmed for the first time that a sub-10-fs pulse is able to efficiently excite a magnetic system such as GdFeCo.

Utilization of temporal dominance of sensations and time intensity methodology for development of low-sodium Mozzarella cheese using a mixture of salts.

Evidence has linked excessive salt consumption to the development of chronic degenerative diseases. Therefore, special attention has been given to the consumption of healthier products with reduced sodium contents. This study aimed to develop a Mozzarella cheese with a reduced sodium content using a mixture of salts through acceptance testing and temporal sensory evaluation. The following 3 formulations of Mozzarella cheese were prepared: formulation A (control), which was produced only with NaCl (0% sodium reduction), formulation B (30% sodium reduction), and formulation C (54% sodium reduction). Every formulation was produced using a mixture of salts consisting of NaCl, KCl, and monosodium glutamate at different concentrations. The products underwent sensory acceptance tests, and the time intensity and temporal dominance of sensations were evaluated. The proportions of salts used did not cause strange or bad tastes but did result in lower intensities of saltiness. Mozzarella with low sodium content (B and C) had a sensory acceptance similar to that of traditional Mozzarella (A). Therefore, the use of a mixture of salts consisting of NaCl, KCl, and monosodium glutamate is a viable alternative for the production of Mozzarella, with up to a 54% reduction in the sodium content while still maintaining acceptable sensory quality.

Selection of high heterozygosity popcorn varieties in Brazil based on SSR markers.

We analyzed genetic structure and diversity among eight populations of popcorn, using SSR loci as genetic markers. Our objectives were to select SSR loci that could be used to estimate genetic diversity within popcorn populations, and to analyze the genetic structure of promising populations with high levels of heterozygosity that could be used in breeding programs. Fifty-seven alleles (3.7 alleles per locus) were detected; the highest effective number of alleles (4.21) and the highest gene diversity (0.763) were found for the Umc2226 locus. A very high level of population differentiation was found (F(ST) = 0.3664), with F(ST) for each locus ranging from 0.1029 (Umc1664) to 0.6010 (Umc2350). This analysis allowed us to identify SSR loci with high levels of heterozygosity and heterozygous varieties, which could be selected for production of inbred lines and for developing new cultivars.

Towards testing the "honeycomb rippling model" in cerrado.

Savannas are tropical formations in which trees and grasses coexist. According to the "honeycomb rippling model", inter-tree competition leads to an effect of trees growing and dying due to competition, which, at fine spatial scale, would resemble honeycomb rippling. The model predicts that the taller the trees, the higher the inter-tree distances and the evenness of inter-tree distances. The model had been corroborated in arid savannas, in what appears to be caused by uneven distribution of rains, but had not yet been tested in seasonal savannas, such as the cerrado, which could be caused by the irregular occurrence of fire.A basic assumption of the model is that strong inter-tree competition affects growth (estimated by height) and mortality (estimated by inter-tree distances). As a first step towards testing this model in the cerrado, we tested this assumption in a single cerrado patch in southeastern Brazil. We placed 80 quadrats, each one with 25 m², in which we sampled all shrubs and trees. For each individual, we measured its height and the distance to its nearest neighbour--the inter-tree distance. We did not find correlations between tree height and both inter-tree distances and evenness of inter-tree distances, refuting the honeycomb rippling model. Inter-tree distances were spatially autocorrelated, but height was not. According to our results, the basic assumption of the model does not apply to seasonal savannas. If, in arid savannas, rainfall events are rare and unpredictable, in seasonal savannas, the rainy season is well-defined and rainfall is considerable. We found horizontal structuring in the community, which may be due to soil nutrient heterogeneity. The absence of vertical structuring suggests that competition for light among adult trees is not as important as competition for nutrients in the soil. We tested the basic assumption of the model in a single patch and at a single moment. To test the model effectively, we suggest this assumption to be tested in many patches over time.

Involvement of median raphe nucleus 5-HT1A receptors in the regulation of generalized anxiety-related defensive behaviours in rats.

Changes in 5-HT1A receptor-mediated neurotransmission at the level of the median raphe nucleus (MRN) are reported to affect the expression of defensive responses that are associated with generalized anxiety disorder (e.g. inhibitory avoidance) but not with panic (e.g. escape). The objective of this study was to further explore the involvement of MRN 5-HT1A receptors in the regulation of generalized anxiety-related behaviours. Results of experiment 1 showed that intra-MRN injection of the 5-HT1A/7 receptor agonist 8-OH-DPAT (0.6 nmol) in male Wistar rats impaired the acquisition of inhibitory avoidance, without interfering with the performance of escape in the elevated T-maze test of anxiety. Pre-treatment with the 5-HT1A receptor antagonist WAY-100635 (0.18 nmol) fully blocked this anxiolytic-like effect. As revealed by experiment 2, intra-MRN injection of 8-OH-DPAT (0.6, 3 or 15 nmol) also caused anxiolytic effect in rats submitted to the light-dark transition test, another animal model that has been associated with generalized anxiety. In the same test, intra-MRN injection of WAY-100635 (0.18, 0.37 or 0.74 nmol) caused the opposite effect. Overall, the current findings support the view that MRN 5-HT neurons, through the regulation of 5-HT1A somatodendritic autoreceptors, are implicated in the regulation of generalized anxiety-associated behaviours.

Hepatocellular carcinoma in Brazil: report of a national survey (Florianópolis, SC, 1995).

In order to investigate epidemiological aspects of hepatocellular carcinoma (HCC) in Brazil, basic informations about cases diagnosed from January 1992 to December 1994 were requested to several medical centers of different Brazilian States. A simple questionnaire included age, sex, alcohol abuse (over 80g/day), associated liver cirrhosis, persistent HBV infection (HBsAg), HCV infection (anti-HCV) and serum levels of alpha fetoprotein. 287 cases, over 16 years old, from 19 medical centers of 8 States (Pará, Bahia, Minas Gerais, Espirito Santo, Rio de Janeiro, São Paulo, Paraná and Rio Grande do Sul) were analysed. The results showed: (a) Mean age was 56.3 +/- 14.4 for men and 54.7 +/- 16.8 yr for women and the male/female ratio was 3.4:1. (b) 69.6% were caucasians, 21.8% mullatoes, 4.8% orientals and 3.7% blacks. (c) HBsAg (+) in 77/236 cases (41.6%) without differences between males and females. (d) Anti-HCV (+) in 52/193 cases (26.9%). (e) 7/180 cases were positive both for HBsAg and anti-HCV (3.8%). (f) There was chronic alcoholism in 88/235 cases (37%). (g) HCC was found in cirrhotic livers in 71.2% of 202 cases in which the presence or absence of cirrhosis was reported. (h) Alpha-fetoprotein above 20 ng/ml was found in 124/172 cases (72%) and above 500 ng/ml only in 40 cases (23.2%). These results showed that the HCC in Brazil has an intermediate epidemiological pattern as compared to those from areas of low and high incidence of the tumor. In spite of the high frequency of the association of HCC with the HBV and/or HCV infections, 42% of 180 cases were negative both for HBsAg and anti-HCV, indicating the possible role of other etiological factors. The comparison of data from different States showed some regional differences: higher frequency of associated HBsAg in Pará, Bahia, Minas Gerais and Espírito Santo, higher frequency of associated HCV infection in Rio de Janeiro, São Paulo and States of the Southern region and low frequency of associated liver cirrhosis in Salvador and Rio de Janeiro (55.5 and 50% respectively). Further investigation will be necessary to study the presence of other possible etiological factors as aflatoxins, suggested by the favourable climatic conditions for food contamination by fungi in the majority Brazilian regions.

The effect of ethanol intake on the development of hepatocellular carcinoma in HBsAg carriers.

To study the effect of alcohol intake on the latency period for the development of hepatocellular carcinoma in a country where this tumor occurs earlier in life than in Southeast of Asia, Europe or North America, 83 male patients with hepatocellular carcinoma aged over 30 years, in which the HBsAg status and ethanol intake were prospectively investigated, were analyzed with respect to age at the time of diagnosis. Only male patients were used because in Vitória, State of Espírito Santo, the age at the time of diagnosis of hepatocellular carcinoma in females is significantly lower than in males. Only patients aged over 30 years were used because the tumor occurs in young people and children, in which habitual alcohol intake is not common. Forty-six patients with hepatocellular carcinoma HBsAg positive and 36 HBsAg negative were separated in alcohol abusers (daily ingestion above 80 g for a period of 10 years or more) or nonalcoholics. The occurrence of associated liver cirrhosis was determined for each group. For comparison of the average age of the four groups the Student t test and the Kruskall-Wallis test for two groups were used. The results showed that the average age of patients with hepatocellular carcinoma HBsAg positive with habitual alcohol intake was significantly lower than those without drinking habit (44.3 +/- 9.7 and 52.3 +/- 15.7 years; P = 0.011 and 0.028 respectively for Student t test and Kruskall-Wallis test). The average age of patients with hepatocellular carcinoma HBsAg (-) with or without habitual ethanol intake showed no significative differences (56.7 +/- 11.3 and 57.3 +/- 12.4 P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

[Primary non-Hodgkin's lymphoma of the liver: report of two cases and review of the literature]. / Linfoma não Hodgkin primitivo do fígado: relato de dois casos e revisão da literatura.

Two cases of primary non-Hodgkin lymphoma of the liver are presented, with comments about the main clinical and pathological aspects of the disease based on literature review. Both patients were woman (19 and 62 years old) and presented the same complaints: severe weight loss and presence of fast growing abdominal mass. In both cases the histologic diagnosis showed a non-Hodgkin, diffuse, large cell lymphoma (centroblastic-centrocytic diffuse lymphoma) with intermediate grade of malignancy. One case (19 years) died before treatment. The autopsy showed a large solitary tumor (18 cm in diameter) in the right liver lobe and two small nodules (1 cm) in the subcutaneous tissue of the abdominal wall. The other case (62 years), was treated by partial hepatectomy and chemotherapy. There was a round, solitary tumor (8 cm in diameter) in the left lobe. The patient remains without manifestations of disease relapse 18 months after the treatment. In both cases the tumor did not spread to lymph nodes, spleen and other viscera.

[Hepatocellular carcinoma]. / Carcinoma hepatocelular.

Hepatocellular carcinoma (HCC), one of the most frequent tumors in the world, is included by the World Health Organization as a relevant public health problem in areas of high incidence as Africa and Southeast of Asia. In this review it will be discussed: a) the close relationship between HCC and hepatitis B virus (HBV), the more universal but not the single etiologic factor having other carcinogens and co-carcinogens involved with the origen of the tumor; b) the great variation in geographic distribution of this tumor, including that of Brazil where the incidence of HCC, including the new macroscopic classification according to the pattern of growth and general with liver cirrhosis in all countries where the tumor is diagnosed; d) some morphological aspects of HCC, including the new macroscopic classification according to the pattern of growth and general characteristics of small HCC; e) the clinical and biochemical aspects, calling attention to the evaluation of serum levels of alpha-fetoprotein, not always increased in patients with HCC, and the immage processing methods, specially ultrassonography, as methods for early diagnosis of HCC, being relevant in the follow-up of high risk patients (cirrhotics HBsAg (+]. Finally some comments are done about the therapeutic methods and perspectives of reduction in the incidence of the tumor with the use of vaccination against HBV infection.

Hepatocellular carcinoma HBsAg positive in pregnancy.

The authors present a case of hepatocellular carcinoma diagnosed in a pregnant woman (four months pregnancy). The clinical evolution was complicated because of a severe hypoglicemia and the patient died 12 weeks after admission. The fetus died before a tentative of surgical delivery. The patient was HBsAg positive and five out of eight sons (inclusively the fetus), were HBsAg positive. There was not indication that the pregnancy had enhanced the tumor evolution.

The association of Schistosoma mansoni infection with hepatocellular carcinoma. / The association of Schistosoma mansoni infection with hepatocellular carcinoma

Foi estudada a associacao de infeccao pelo Schistosoma mansoni em pacientes portadores de carcinoma hepatocelular (CHC) diagnosticados no Espirito Santo. O dignostico de esquistossomose foi feito pelo exame parasitologico das fezes ou pelos achados histologicos a necropsia. O diagnostico de CHC foi feito por laparoscopia e biopsia, somente biopsia ou por necropsia. Entre 45 casos de CHC, seis apresentavam infeccao pelo S. mansoni (13,04%). A ocorrencia de infeccao esquistossomotica nos CHC HBsAg positivos ou negativos foi semelhante (13,33 e 13,63% respectivamente). A comparacao pelo metodo do qui quadrado nao mostrou diferenca significativa entre a frequencia de infeccao esquistossomotica nos pacientes com CHC e a frequencia de esquistossomose na populacao que vive no E.Santo (5,97%) entre criancas do curso primario de todas as regioes do Estado e 6,75% entre a populacao que procura recursos medicos em Vitoria, a capital do Estado). Desta forma os autores acreditam que a associacao de infeccao esquistossomotica e CHC deve ser casual, especialmente nas areas onde a esquistossomose e frequente

Hepatocellular carcinoma HBsAg positive in pregnancy.

Um caso de carcinoma hepato-celular diagnosticado no quarto mes de gravidez, e relatado. A evolucao clinica foi complicada por hipoglicemia severa, tendo a paciente falecido 12 semanas apos a internacao. O feto morreu antes de se tentar parto cirurgico. A paciente era AgHbs positivo, assim como cinco de seus oito filhos (inclusive o feto). Nao houve indicacao de que a gravidez tivesse aumentado o crescimento tumoral

[Alcoholic hepatitis: clinical, laboratorial and histological study of 50 cases]. / Hepatite alcoólica: estudo clínico, laboratorial e histológico de 50 casos.

The clinical, laboratorial and histological aspects of 50 cases of alcoholic hepatitis were analysed, as well as the follow-up of 24 patients. The mean age of the 50 patients was 42,9 years (range: 25 to 65 years); 44 were males. The beginning of the symptomatology was insidious in great number of cases. The hepatomegaly was most habitual clinical signal (92% of cases). The jaundice was observed in 58% of the cases. Twenty six per cent of the patients had not manifestation of advanced hepatopaty at the moment of diagnosis. The most constant laboratorial alteration (except the increase of gama-glutamil-transpeptidase, dosed in rare cases) was the increase of SGOT (94%). Histological examination showed necrosis and inflammatory exudate in all cases; steatosis in 98%; Mallory bodies in 78%; fibrosis in 84%; cirrhosis in 44%. In the group of patients that came to the obit at the first internation, jaundice, digestive bleeding, encephalopathy, infection, leucocitosis and decreased prothrombin activity. The follow-up of 24 cases (3 months to 5 years) showed aggravation of illness and frequent evolution to cirrhosis in patient that maintained the alcohol ingestion.

Hepatite alcoolica: estudo clinico, laboratorial e histologico de 50 casos. / Alcholic hepatitis: clinical, laboratorial and histological study of 50 cases

Os aspectos clinicos, laboratoriais e histologicos de 50 casos consecutivos de hepatite alcoolica sao analisados, bem como a evolucao tardia de 24 pacientes. Quarenta e quatro eram masculinos, a idade variando de 25 a 62 anos, com media de 42,9. Na maioria dos casos, o inicio da sintomatologia foi insidioso. A hepatomegalia foi o sinal clinico mais comum (92%); ictericia foi observada em 58% dos casos. Vinte e seis por cento dos pacientes nao apresentavam sinais ou sintomas sugestivos de hepatopatia avancada, na epoca do diagnostico. A alteracao laboratorial mais constante, excluindo a dosagem da gamaglutamil-transpeptidase (dosada em poucos casos), foi a elevacao da transaminase oxalacetica (94%). Histologicamente observamos necrose e infiltrado inflamatorio em todos os casos, esteatose em 98%, corpusculo de Mallory em 44%. No grupo que evoluiu para o obito na primeira internacao, foram significativamente mais frequentes a ictericia, hemorragia digestiva, encefalopatia, sinais de infeccao leucocitose e baixa atividade de protrombina.Em 24 casos acompanhados (3 meses a 5 anos) observou-se piora do quadro e alta frequencia de evolucao para cirrose, nos pacientes que mantiveram o alcoolismo

The association of hepatitis B surface antigen (HBs Ag) with hepatocellular carcinoma in Espírito Santo State, Brazil.

1. The occurrence of hepatitis B surface antigen (HBs Ag) was investigated in 46 cases of hepatocellular carcinoma (HCC) diagnosed in Vitória, Espírito Santo State, Brazil. 2. Twenty cases were patients in which the HCC was diagnosed by biopsy, laparoscopy or on autopsy from 1977 to 1980. HBs Ag was measured in the serum by reverse passive hemagglutination (13 cases) and radioimmunoassay (7 cases). Twelve cases (60%) were HBs Ag positive. 3. The presence of HBs Ag was studied in 26 cases diagnosed on autopsy using paraffin-embedded liver sections stained with orcein. Eleven cases (42%) showed orcein granules in hepatocytes surrounding the tumor. In only one case were orcein-positive granules detected in the tumor cells. 4. The 50% incidence of HBs Ag among patients with HCC is higher than the occurrence of HBs Ag in the general population of the State of Espírito Santo, i.e. 3.5% among 1300 blood donors to the University Hospital. 5. These data provide additional evidence for the hypothesis that there is a relationship between the hepatitis B virus and the etiology of HCC.