Analysis of earlier times and flux of entropy on the majority voter model with diffusion.

We study the properties of nonequilibrium systems modelled as spin models without defined Hamiltonian as the majority voter model. This model has transition probabilities that do not satisfy the condition of detailed balance. The lack of detailed balance leads to entropy production phenomena, which are a hallmark of the irreversibility. By considering that voters can diffuse on the lattice we analyze how the entropy production and how the critical properties are affected by this diffusion. We also explore two important aspects of the diffusion effects on the majority voter model by studying entropy production and entropy flux via time-dependent and steady-state simulations. This study is completed by calculating some critical exponents as function of the diffusion probability.

Nonequilibrium critical dynamics of the two-dimensional Ashkin-Teller model at the Baxter line.

We investigate the short-time universal behavior of the two-dimensional Ashkin-Teller model at the Baxter line by performing time-dependent Monte Carlo simulations. First, as preparatory results, we obtain the critical parameters by searching the optimal power-law decay of the magnetization. Thus, the dynamic critical exponents θ_{m} and θ_{p}, related to the magnetic and electric order parameters, as well as the persistence exponent θ_{g}, are estimated using heat-bath Monte Carlo simulations. In addition, we estimate the dynamic exponent z and the static critical exponents ß and ν for both order parameters. We propose a refined method to estimate the static exponents that considers two different averages: one that combines an internal average using several seeds with another, which is taken over temporal variations in the power laws. Moreover, we also performed the bootstrapping method for a complementary analysis. Our results show that the ratio ß/ν exhibits universal behavior along the critical line corroborating the conjecture for both magnetization and polarization.

Nonequilibrium scaling explorations on a two-dimensional Z(5)-symmetric model.

We have investigated the dynamic critical behavior of the two-dimensional Z(5)-symmetric spin model by using short-time Monte Carlo (MC) simulations. We have obtained estimates of some critical points in its rich phase diagram and included, among the usual critical lines the study of first-order (weak) transition by looking into the order-disorder phase transition. In addition, we also investigated the soft-disorder phase transition by considering empiric methods. A study of the behavior of ß/νz along the self-dual critical line has been performed and special attention has been devoted to the critical bifurcation point, or Fateev-Zamolodchikov (FZ) point. First, by using a refinement method and taking into account simulations out of equilibrium, we were able to localize parameters of this point. In a second part of our study, we turned our attention to the behavior of the model at the early stage of its time evolution in order to find the dynamic critical exponent z as well as the static critical exponents ß and ν of the FZ point on square lattices. The values of the static critical exponents and parameters are in good agreement with the exact results, and the dynamic critical exponent z≈2.28 very close to the four-state Potts model (z≈2.29).

Mini-fasting tests diagnosing endogenous hyperinsulinism: a follow-up of 26 cases.

CONTEXT: The supervised 72-h fast remains the gold standard test for the diagnosis of endogenous hyperinsulinism and has recently been suggested to be shortened or even avoided. OBJECTIVE: This study aimed to evaluate whether measurement of blood glucose, insulin and C-peptide levels after a 12 h overnight fast (mini-fasting test), in at least 3 consecutive days, could allow making or ruling out diagnosis of endogenous hyperinsulinism, according to the Endocrine Society's recent guidelines. PATIENTS AND METHODS: We performed 12 h mini-fasting test in at least 3 consecutive days, dosing blood glucose, insulin and C-peptide levels in 26 inpatient patients with pathologically proven endogenous hyperinsulinism. RESULTS: In our series, 100% of patients showed insulin levels of at least 3 µU/ml and C-peptide levels of at least 0.6 ng/ml concomitant with symptomatic hypoglycemia (≤ 55 mg/dl). CONCLUSION: It leads to the conclusion that mini-fasting test might avoid, in most cases, prolonged fasting test for the diagnosis of hypoglycemia due to endogenous hyperinsulinism.

Glucagon test in insulinoma: Is it useful?

Diagnosis of endogenous hyperinsulinism caused by insulinoma is based on confirmation of hypoglycemia during the symptoms associated to elevated insulin levels. Patients with insulinoma may demonstrate an excessive insulin response and subsequent hypoglycemia after 1 mg of glucagon iv injection. Glucagon test was performed in 11 patients with insulinoma before therapy and in 4 after therapy. Our study suggests that the presence of plasma glucose levels less than 55 mg/dl and below baseline at time 120 min of glucagon test strongly reinforce the diagnosis of insulinoma.

Global persistence exponent of the double-exchange model.

We obtained the global persistence exponent for a continuous spin model on the simple cubic lattice with double-exchange interaction by using two different methods. First, we estimated the exponent theta(g) by following the time evolution of probability P(t) that the order parameter of the model does not change its sign up to time t[P(t) approximately t(-theta(g)]. Afterwards, that exponent was estimated through the scaling collapse of the universal function L(theta(g)(z)P(t) for different lattice sizes. Our results for both approaches are in very good agreement with each other.

Short-time dynamics of the helix-coil transition in polypeptides.

We study the critical relaxation of the helix-coil transition in all-atom models of polyalanine chains. We show that at the critical temperature the decay of a completely helical conformation can be described by scaling relations that allow us estimating the pertinent critical exponents. The present approach opens a new way for characterizing transitions in proteins and may lead to a better understanding of their folding mechanism. An application of the technique to the 34-residue human parathyroid fragment PTH(1-34) supports universality of the helix-coil transition in homopolymers and (helical) proteins.

Ocorrência de aflatoxina m1 em leite comercializado em alguns municípios do estado de são paulo / Occurrence of m1 aflatoxin in milk commercialized in some cities of são paulo state, brazil

RESUMO A aflatoxina M1 (AFM1) tem sido detectada em leite de animais alimentados com ração contaminada por aflatoxina B1(AFB1). A ocorrência de aflatoxina M1 no leite de vacas lactantes é uma questão de saúde pública, pois o leite e seus derivados são consumidos por bebês, crianças e adultos em todo mundo. Essa toxina é classificada como possível carcinógeno para o homem (classe 2B). O objetivo deste trabalho foi verificar a qualidade do leite consumido em algumas regiões do Estado de São Paulo, quanto ao teor de aflatoxina M1. Foram analisadas 43 amostras de leite comercial, coletadas em 27 municípios do Estado de São Paulo. A determinação de AFM1 em leite foi realizada empregando-se coluna de imunoafinidade para a purificação e detecção por cromatografia líquida de alta eficiência em fase reversa. AFM1 foi detectada em 17 (39,5%) das 43 amostras analisadas, sendo que 64,7% destas amostras apresentavam concentrações acima do limite máximo permitido pela legislação (0,5 µg/L).

ABSTRACT The M1 aflatoxin (AFM1) has been detected in milk from animal fed with feed contaminated by aflatoxin B1 (AFB1) contaminated. This toxin is a possible carcinogenic to humans (2B class). This is a potential public health problem, because young individuals are among the greater milk consumers and more sensitive to it effects. This study was developed to determine AFM1 in pasteurized milk in same regions São Paulo state. Forty-three samples colected in several cities were analized. The method used for the M1 aflatoxins purification was the immunoafinity column, with subsequent detection by reverse phase HPLC. AFM1 was detected in 17 (39.5%) out of 43 samples, 64.7% of the contaminated samples were above 0.5 µg/L

Avaliação acaricida de produtos naturais para o controle de ácaro vermelho do cafeeiro oligonychus ilicis (mcgregor) (acari: tetranychidae) / Evaluation of plant extracts for the control of coffee red mite oligonychus ilicis (mcgregor) (acari: tetranychidae)

RESUMO O ácaro Oligonychus ilicis apresenta ampla distribuição no Estado de São Paulo, com maiores incidências nos períodos mais secos do ano. Estes ácaros possuem o hábito de estarem presentes na página superior das folhas do cafeeiro. Foram avaliados no controle deste ácaro, extratos aquosos, etanólicos e hexânicos de Lavandula angustifolia Mill., Dahlia pinnata Cav., Solanum paniculatum L., Agave angustifolia Haw, Ocimum basilicum L., Solanum melongena L., Rhododendron simsii Planch., Ficus elastica Roxb, Codiaeum variegatum (L.) Bl., Spondias purpurea L., Sonchus oleraceus L., Ruta graveolens L., Annona squamosa L., Pennisetum purpureum Schumach., Dieffenbachia brasiliensis (Veiech) e Allamanda cathartica L. Discos foliares de café var. Mundo Novo foram mergulhados na solução de extrato por 5seg e as fêmeas adultas em número de 20 por parcela confinadas na superfície do disco e mantidas em câmara incubadora a 25 ± 2º C e 70 ± 10% UR. Avaliação de mortalidade foi realizada com 48h. Os melhores resultados em eficiência foram obtidos com os extratos etanólico e hexânico de Dieffenbachia brasiliensis (56 e 52%), D. pinnata (54%), Allamanda cathartica (44%) e S. paniculatum (46 e 48%).

ABSTRACT The coffee red mite Oligonychus ilicis, is widespread in the state of São Paulo, with higher incidence on coffee plantations during the dry seasons. These mites live almost exclusively on the top side of the host leaves. Evaluations of aqueous, ethanolic and hexanic extracts were made for Lavandula angustifolia Mill., Dahlia pinnata Cav., Solanum paniculatum L., Agave angustifolia Haw, Ocimum basilicum L., Solanum melongena L., Rhododendron simsii Planch., Ficus elastica Roxb, Codiaeum variegatum (L.) Bl., Spondias purpurea L., Sonchus oleraceus L., Ruta graveolens L., Annona squamosa L., Pennisetum purpureum Schumach., Dieffenbachia brasiliensis (Veiech) and Allamanda cathartica L. Foliar discs of coffee var. Novo Mundo were immersed in the extract solution for 5 seconds and adult females (20 per replication) were confined on the surface of the disc and kept in an incubator chamber at 25 ± 2º C and 70 ± 10% RU. Survey of the mortality was taken at 48h. The best results of efficiency were obtained with the ethanolic and hexanic extracts of: Dieffenbachia brasiliensis (56 and 52%), D. pinnata (54%), Allamanda cathartica (44%) and S. paniculatum (46 and 48%).

Critical behavior of nonequilibrium models in short-time Monte Carlo simulations.

We analyze two alternative methods for determining the dynamic critical exponent z of the contact process and the Domany-Kinzel cellular automaton in Monte Carlo simulations. One method employs mixed initial conditions, as proposed for magnetic models [Phys. Lett. A 298, 325 (2002)]]; the other is based on the growth of the moment ratio m (t) = /2 starting with all sites occupied. The methods provide reliable estimates for z using the short-time dynamics of the process. Estimates of nu|| are obtained using a method suggested by Grassberger.

Global persistence exponent of the two-dimensional Blume-Capel model.

The global persistence exponent theta(g) is calculated for the two-dimensional Blume-Capel model following a quench to the critical point from both disordered states and such with small initial magnetizations. Estimates are obtained for the nonequilibrium critical dynamics on the critical line and at the tricritical point. Ising-like universality is observed along the critical line and a different value theta(g)=1.080(4) is found at the tricritical point.

Short-time critical dynamics of the Baxter-Wu model.

We study the early time behavior of the Baxter-Wu model, an Ising model with three-spin interactions on a triangular lattice. Our estimates for the dynamic exponent z are compatible with results recently obtained for two models which belong to the same universality class of the Baxter-Wu model: the two-dimensional four-state Potts model and the Ising model with three-spin interactions in one direction. However, our estimates for the dynamic exponent theta of the Baxter-Wu model are completely different from the values obtained for those models. This discrepancy could be related to the absence of a marginal operator in the Baxter-Wu model.

Universality and scaling study of the critical behavior of the two-dimensional Blume-Capel model in short-time dynamics.

In this paper we study the short-time behavior of the Blume-Capel model at the tricritical point as well as along the second order critical line. Dynamic and static exponents are estimated by exploring scaling relations for the magnetization and its moments at an early stage of the dynamic evolution. Our estimates for the dynamic exponents, at the tricritical point, are z=2.215(2) and theta=-0.53(2).

Biflavonoids inhibit the production of aflatoxin by Aspergillus flavus

The biflavonoids 6,6"-bigenkwanin, amenthoflavone, 7,7"-dimethoxyagastisflavone and tetradimethoxybigenkwanin isolated from Ouratea species were tested for inhibitory activity on Aspergillus flavus cultures. Suspensions of Aspergillus flavus spores were inoculated into 50 ml of YES medium at different biflavonoid concentrations: 5 and 10 æg/ml for 6,6"-bigenkwanin, amenthoflavone and 7,7"-dimethoxyagastisflavone, and 5, 10, 15 and 20 æg/ml for tetradimethoxybigenkwanin. The four biflavonoids showed inhibitory activity on aflatoxin B1 and B2 production (P<0.001), but did not inhibit fungal growth at the concentration tested (P>0.05). These results show that biflavonoids can be used for the development of agents to control aflatoxin production

Biflavonoids inhibit the production of aflatoxin by Aspergillus flavus.

The biflavonoids 6,6"-bigenkwanin, amenthoflavone, 7,7"-dimethoxyagastisflavone and tetradimethoxybigenkwanin isolated from Ouratea species were tested for inhibitory activity on Aspergillus flavus cultures. Suspensions of Aspergillus flavus spores were inoculated into 50 ml of YES medium at different biflavonoid concentrations: 5 and 10 microg/ml for 6,6"-bigenkwanin, amenthoflavone and 7,7"-dimethoxyagastisflavone, and 5, 10, 15 and 20 microg/ml for tetradimethoxybigenkwanin. The four biflavonoids showed inhibitory activity on aflatoxin B1 and B2 production (P<0.001), but did not inhibit fungal growth at the concentration tested (P>0.05). These results show that biflavonoids can be used for the development of agents to control aflatoxin production.

Biflavonoids from Ouratea multiflora.

A new flavone dimer, 3-hydroxy-4',5,7-trimethoxyflavone-(6-->8")-3"-hydroxy-3"',4"', 5",7"-tetramethoxyflavone, together with amenthoflavone, have been isolated from the leaves of Ouratea multiflora. Its structure was established by spectroscopic methods, including two-dimensional NMR spectroscopy.

Effect of blood glucose on left ventricular mass in patients with hypertension and type 2 diabetes mellitus.

The aim of our prospective study was to evaluate the influence of blood glucose (BG) on left ventricular mass and diastolic function in patients with hypertension and type 2 diabetes mellitus (DM). Fifty-six hypertensive patients with type 2 DM and 26 healthy controls were investigated. They were submitted to echocardiography (ECHO) with Doppler and we calculated the mean of their fasting BG values, office blood pressure (OBP), cholesterol and fractions, and triglycerides during the previous 4 years. The diabetic patients were then followed-up for 1 year with OBP, fasting BG, and lipids measured every 2 months. After this period, the patients were again submitted to ECHO and in 22 patients (group I [GI]), reductions greater than 10% in left ventricular mass index (LVMI) were observed (122 +/- 35 v 89 +/- 23 g/m2, P < .01), whereas increases greater than 10% (group II [GII], n = 17) (94 +/- 18 v 115 +/- 27 g/m2, P < .01) or no changes (group III [GIII], n = 17) (98 +/- 16 v 99 +/- 18 g/m2, NS) in LVMI were detected in the remaining patients. The OBP values did not change during the follow-up. In GI the reduction of LVMI was associated with a BG fall from 178 +/- 36 to 147 +/- 30 mg/dL (P < .01) and a correlation was observed between BG and LVMI percent variations (delta) (r = 0.48, P < .01). No important changes in left ventricular diastolic function were observed during the follow-up. We concluded that the improvement in glycemic control may contribute to LVH regression in hypertensive patients with type 2 DM.

Antiviral activity of crude extracts of Guarea guidona.

Crude extracts of leaves and fruits of Guarea guidona were tested for antiviral activity against pseudorabies virus and foot-and-mouth disease virus in the IB-RS-2 pig cell line and against bovine herpesvirus-1 (BHV-1) in the GBK bovine cell line. The highest nontoxic doses of extracts from fruits and leaves were 125 micrograms/ml and 500 micrograms/ml. respectively. Crude extracts presented antiviral activity against pseudorabies virus with a decrease in virus titer of 3.0 log units at 500 micrograms/ml. Virucidal activity was not observed at 62.5 micrograms/ml. Preformed cell monolayers showed no cytotoxic effect after 48 h in the presence of 500 micrograms/ml in pig cells. G. guidona leaves did not induce an antiviral state but exhibited antiviral effects during the early stage of viral infection.

Antiviral activity of crude extracts of Guarea guidona

Crude extracts of leaves and fruits of Guarea guidona were tested antiviral activity against pseudorabies virus and foot-and-mouth disease virus in the IB-RS-2 pig cell line and against bovine herpesvirus-1 (BHV-1) in the GBK bovine Cell line. The highest nontoxic doses of extracts from fruits and leaves were 125 mug/ml and 500 mug/ml, respectively. Crude extracts presented antiviral activity against pseudorabies virus with a decrease in virus titer of 3.0 log units at 500 mug/ml. Virucidal activity was not observed at 62.5 mug/ml. Preformed cell monolayers showed no cytotoxic effect after 48 h in the presence of 500 mug/ml in pig cells. G. guidona leaves did not induce an antiviral state but exhibited antiviral effects during the early stage of viral infection.

Inhibition of lens aldose reductase by biflavones from Ouratea spectabilis.

Two biflavonoids were isolated from the EtOH extract from leaves of Ouratea spectabilis. Their structures were established to be the novel 6,6"-bigenkwanin and 7,7"-dimethoxyagathisflavone on the basis of spectroscopic data. The inhibition of bovine lens aldose reductase exerted by these biflavones has been studied.