Concentração, proporção molar e taxa de produção de ácidos graxos voláteis (AGV) no rúmen de bovinos alimentados com diferentes níveis de concentrado na dieta

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito dose-resposta de uma formulação de dentifrício com concentração reduzida de fluoreto - estudo in vitro.

The utilization of dentifrices with low fluorine concentration, for children under 6 years of age, has been suggested to reduce the risks of dental fluorosis. However, in order to have anticariogenic potential, the dentifrice should form loosely-bound fluorine (CaF2) on dental enamel. Considering that the formation of CaF2 is a function inversely related to pH, dentifrices with pH 5.5, with 275, 550 and 1,100 ppm F (NaF/silica) were developed in order to assess dose-response effects. A comparison between those dentifrices, a placebo product and the Crest toothpaste (positive control - standard) was carried out. Furthermore, the bioavailability of dentifrices, in terms of formation of total fluorine (TF), CaF2, and fluorapatite (FA) on human dental enamel, was evaluated. An ion-specific electrode was utilized for the determination of the dosage of fluorine. The results revealed that the dentifrice with 550 ppm F was more effective than both the placebo and the dentifrice with 275 ppm, presenting no difference in relation to the positive control (p > 0.05). A dose-effect correlation was observed as to the CaF2 formed. In conclusion, the modified formulation with 550 ppm F can be considered as effective as the standard dentifrice with 1,100 ppm, and its utilization would be safer with regard to dental fluorosis.

Influência da concentração de antioxidante na estabilidade do ácido retinóico

Retinoic acid, which has been prescribed for some forms of acne since 1962, is subject to isomerization provoked by atmospheric oxygen and ambient light. Therefore it is very important to keep this material intact through the use of antioxidants. We tested two antioxidants: various concentrations of butylhydroxytoluene or BHT, widely used in cosmetic and dermatological preparations, and vitamin E, found in grape oil, an ingredient of skin lotion. Recently prepared lotions were subject to heat stress and the residual concentrations of retinoic acid determined at predetermined intervals through UV spectrophotometry. The shelf life of the various preparations were determined by the Arrhenius equation. The antioxidants helped conserve the retinoic acid, however, there was no synergism in antioxidant activity between the vitamin E in the grape seed oil and BHT.

Matéria seca, concentração e acúmulo de nutrientes em mudas de Eucalyptus grandis em função da idade

E grandis seedlings of Bofete progeny, cultivated in nurseries of Eucatex Florestal, were collected at ages of 55, 69, 83, and 97 days, separated into leaves, stem, and roots. The seedlings were then placed in identified paper bags, and oven-dried until weight became constant. They were then weighed and chemically analyzed for the determinate of dry matter production, concentrations and accumulation of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn in the several seedling ages. The distribution of total dry matter weight complied with the following descending order: leaf > stem > roots. Conversely to expectations, the highest concentrations of nutrients occurred in leaves for N and Mn only. Seedling hardened process resulted in N and S deficiency. The sequence of macronutrient concentration in seedlings at the time of shipment was the following: leaf > root > stem for N; root = stem > leaf for P; leaf = root = stem for K; stem > root > leaf for Ca; root > leaf > stem for Mg and S. All macronutrient concentrations in organs decreased with age, except for Ca. Concentrations of Cu, Fe, and Zn in all seedling specimens decreased with age. The sequence of micronutrient concentrations in seedling specimens at the time of shipment was the following: root >stem = leaf for B; root > stem > leaf for Cu and Fe; root > leaf > stem for Zn, and leaf > stem > root for Mn. At the time of shipment, at 97 days of age, K was the most extracted macronutrient of all, followed in a descending order by Ca, N, Mg, P, and e S. At the end of the seedling production rotation, Mn was the most extracted micronutrient, followed by Fe, Zn, Cu, and B.

Concentração de flúor nas águas de abastecimento público de municípios da região noroeste do estado de São Paulo, Brasil

It may be difficult for small and medium cities to obtain information about the fluoride content of public water, because of the lack of equipments and technicians. This study aimed to analyze the fluoride levels of the water supplied by the public treatment stations of 40 cities situated in the northwest region of São Paulo State, during a period of 6 months, to verify if fluoridation occurs in a continuous manner and if the fluoride levels are within the recommended. Maps of the water distribution system were obtained from the water treatment companies and utilized to randomize the addresses of the collection sites, so that they included all regions with treated water sources. One water sample by month was collected and analyzed in duplicate using an ion-specific-electrode. Samples with 0.6 to 0.8 mgF/L were considered acceptable. In the 38 cities that regularly provided the samples in the 6 months of the study, water from 144 collection sites was collected and a total of 864 samples were analyzed, of which 61.81 percent were classified as unacceptable. It was observed that 33 cities performed fluoridation but in 78.79 percent of these cities there were variations in the fluoride level among the sites and in the same site during the period of study. One can conclude that most of these cities do not control the fluoride levels in the public water, since fluoridation occurs in a discontinuous manner and in most of the situations not within the recommended concentrations.

Concentração de sais da soluçtiao avaliada pela condutividade elétrica na zona radicular do crisântema sob irrigação por gotejamento

The effects of salt concentration levels in electrical conductivity (EC) were evaluated in chrysanthemum root, cultivated in substrate using two sampling methods, under greenhouse conditions. The experiment was carried out in Paranapanema, São Paulo using the experimental design in randomized blocks and four replications. The treatments consisted of eight sampling periods of substrate solutions in pots: 7, 14, 21, 28, 35, 42, 49 and 56 days after strike root and five salt concentration levels of applied saline solution: 1.42; 1.65; 1.89; 2.13 and 2.36 dS m -1 in the vegetative period and during the reproduction period of flower budding: 1.71; 1.97; 2.28; 2.57 and 2.85 dS m -1. The substrate solution EC monitoring was done using two methods: solution extractors and 1:2 water diluted solution. The use of solution extractors and 1:2 water diluted solution allowed substrate solution EC monitoring along the culture cycle; the amount of salt concentration applied in the substrate caused the substrate salinity increase; the method using solution extractors presented higher EC values in the substrate.

Potential anticariogênico de soluções aciduladas com baixa concentração flúor

Objetives: The aim of this study was to verify the anticariogenic effect of acidulate solutions with low NaF concentration, using pH-cycling model and bovine enamel. Material and methods: Enamel blocks were submitted to the surface microhardness (SMH) test and randomly divided in 12 experimental and one placebo groups. The blocks were submitted to pH cycling for 7 days, with daily applications once/day of 0.05% NaF and 0.1% NaF and twice/day of 0.02% NaF solutions. Four different pH: 4.0. 5.0, 6.0 and 7.0 were used. Next, SMH test was again used to determine the surface microhardness percentage change (%SMH). Data obtained for %SMH were homogeneous and passed through variance analyses and Tukey's test (5%) as far as fluoride concentrations and pH. Resulls:The results showed that pH influenced %SMH in 0.02% NaF and 0.05% NaF solutions with pH 4.0, which had less mineral loss compared to pH 7.0 (p̃0.05). The 0.02% NaF - pH 4.0, and 0.05% NaF- pH 7.0 groups showed similar results (p>0.05). A dose-response relationship was observed among the tested solutions, with better anticariogenic effect for the 0.1% NaF solution. Conclusion: The results suggest that the addition of citric acid to acidulate mouth rinses reduce mineral loss.

Avaliação da liberação de lh e da concentração de progesterona em protocolos ovsynch e heatsynch em bubalinos (bubalus bubalis)

The objective of this study was to evaluate the LH surge after last hormonal injection of synchronization of ovulation protocols in buffalo. Fifteen multiparous buffaloes received 25 mg of Lecirelin in Day 0, and 150 mg of D-Cloprostenol on Day 7. On Day 8, estradiol benzoate was injected in Group 1 (0.5 mg, n = 5) and Group 2 (1.0 mg, n = 5). On Day 9, five buffaloes received 25 mg of Lecirelin (Control). Blood samples were collected for measure the LH concentrations on Day 7 and then every 3 hours until 72 hours after the PGF 2a injection. For evaluation of LH surge were compared the interval between PGF 2a injection to LH surge, duration, amplitude and area under the LH peak. The LH surge occurred 51.0 + 0.0 hours, 47.3 + 2.7 hours and 47.0 + 3.8 hours after PGF 2a injection for Control, Group 1 and Group 2, respectively (P > 0.05). The duration of LH peak in Control (7.8 + 1.5 hours) was shorter than Groups 1 and 2 (10.5 + 1.5 hours vs. 10.8 + 2.4 hours, respectively; P < 0.05). The amplitudes of LH peak were 4.5 + 0.4 ng/mL, 4.0 + 0.4 ng/mL and 4.3 + 0.8 ng/mL for Control, Group 1 and Group 2, respectively (P > 0.05). The area under LH peak for Control (4.8 ± 0.7) was smaller than the areas of the Groups 1 and 2 (8.8 ± 2.5 vs. 8.7 2.2, respectively; P < 0.05). In summary, the estradiol benzoate injection provided higher duration and area of LH peak than GnRH injection in Ovsynch protocol in buffalo.

Lipoperoxidação, perda de viabilidade celular e diminuição da liberação de IL-8 de neutrófilos humanos na presença de corpos cetônicos

Type-1 diabetes patients suffer from frequent episodes of acidosis caused by an increased fatty acid metabolism and consequently increased plasma level of acetoacetate (AcAc) and β-hydroxybutyrate (β-HOB). This article describes a study of the effects of pathological concentrations of AcAc and β-HOB on lipoperoxidation, cell viability and the release of the CXCL8 (IL-8) cytokine by activated neutrophils. Neutrophils from healthy donors were isolated by density gradient (Histopaque® 1077/1119) and incubated with the ketone bodies. Lipoperoxidation was determined as thiobarbituric acid reactive substances (TBARS). The cell viability was evaluated by the release of intracellular lactate dehydrogenase. The release of CXCL8 was measured by ELISA in a 24-h culture of opsonized zymosan-stimulated neutrophils. AcAc, but not β-HOB, provoked a dose-dependent increase in the neutrophil membrane lipoperoxidation (p<0.05; r =0.9915). In the cytotoxicity assay, a dose-dependent release of LDH was observed when the neutrophils were incubated with AcAc in concentrations up to 40 mM (p<0.05). β-HOB was devoid of effect. The release of CXCL8 was inhibited by AcAc and β-HOB in a dose-dependent manner. In conclusion, these results suggest that the accumulation of ketone bodies in diabetic patients could be involved in their usually increased susceptibility to infection.

Controle de erosão em estradas rurais não pavimentadas, utilizando sistema de terraceamento com gradiente associado a bacias de captação

The agricultural unpaved roads are important road structures for the economic and social agricultural development of the Nation, and the erosion provoked by rain water in the road bed and sides are closely related to bad draining, one of the main factors for their degradation. In order to make the draining system adequate, it is necessary to know about erodibility, infiltration capacity of water in the ground and adoption of mechanical slope abatement with grid elevation and water interception. This study presents drainage model through the construction of terraces with gradient transversally associated to the capitation basin in abruptic red dystrophic argisol soils, medium sandy texture, based on slops abatement techniques, elevating the road bed and deviating flow. The grain sized fractions of this ground (sand, silt, clay) and the aggregate stability indicated that this ground, under anthropic action, presents erosive processes resulting in superficial draining with ground hauling, sanding sources and courses of water situation below roads, providing great environmental impacts in the hydric bodies. The reduction of erosion problems in these unpaved roads is in the adoption of measures that intercept waters from the draining of their stream bed itself, as well as pluvial waters comings from adjacent areas of contribution, that are collected and conducted to inlaid terraces and capitation basis.

Efeito da suplementação com selênio sobre a concentração sérica de creatina kinase em bovinos

The study, evaluated the addition of different concentrations of Se in mineral mixture affecting creatine kinase (CK) serum concentrations in cattle. 60 male, Nellore cattle, at about 12 months old, were randomly assigned to groups (15 calves/ group), Gc, G3,6, G5,4 or G6,4 (0, 3.6, 5.4, and 6.4 mg Se/bovine/day). The levels of serum CK in the cattle were not affected by neither the interaction selenium concentration x time nor the concentration of supplementation. However, CK levels increased over the experiment irrespective of dietary selenium concentration. In addition, the frequency of animals with CK levels above normal increased (p<0.10) in group G6,4. The concentrations of selenium studied here do not affect serum CK in cattle, but the daily concentration of 6.4 mg selenium is not recommended because it is possibly toxic effect.

Variabilidade temporal e meridional de estimativas de Satélite da concentração de clorofila superficial na plataforma continental brasileira

Forecast of biological consequences of climate changes depend on both long-term observations and the establishment of carbon budgets within pelagic ecosystems, including the assessment of biomasses and activities of all players in the global carbon cycle. Approximately 25% of oceanic primary happen over continental shelves, so these are important sites for studies of global carbon dynamics. The Brazilian Continental Shelf (BCS) has sparse and non-systematic in situ information on phytoplankton biomass, making products derived from ocean color remote sensing extremely valuable. This work analyzes chlorophyll concentration (Chl) estimated from four ocean color sensors (CZCS, OCTS, SeaWiFS and MODIS) over the BCS, to compare Chl and annual cycles meridionally. Also, useful complementary ocean color variables are presented. Chl gradients increased from the central region towards north and south, limited by estuarine plumes of Amazon and La Plata rivers, and clear annual Chl cycles appear in most areas. In southern and central areas, annual cycles show strong seasonal variability while interannual and long-term variability are equally important in the remaining areas. This is the first comparative evaluation of the Chl over the BCS and will aid the understanding of its long-term variability; essential initial step for discussions of climate changes.

Parâmetros físicos pré-eruptivos do magmatismo ácido da província magmática do Paraná: Resultados preliminares

A set of 12 samples of acid rock types Palmas (ATP) and Chapecó (ATC) was used to determine the chemical composition of plagioclase and pyroxene by electron microprobe, with the purpose to get information about the pressure and temperature of crystallization of these rocks. The results show that the pyroxene of ATP rocks (3,2 ± 1,2 kbar, max = 5,1 kbar and 1028 ± 38°C) were formed under pressure conditions higher than those ATC (1,8 ± 0,9 kbar, max = 3,4 kbar and 995 ± 26oC). However, the pressures obtained from plagioclase showed higher pressures for ATC (3.2 ± 1 kbar, max = 6,4 kbar and 1033 ± 12°C) than ATP (1,9 ± 1 kbar, max = 4,8 kbar and 1043 ± 5°C), suggesting that the crystallization of rocktype ATP began with the formation of pyroxene and plagioclase almost simultaneously at a depth of around 17 km while the ATC, began with the crystallization of plagioclase at a depth of about 21 km (assuming a gradient of 3,3 kbar/km). The geothermometry of plagioclase allow us to calculate the concentration of water from about 1 ± 0,3% H2O for both acid rock types. Additional calculations allow us to get the depth of water exsolution of magmatic liquid at 30m below the surface. Although the data are still preliminary and insufficient to model the extrusion of these rocks, they point out to an effusion mechanism of a partially fluidized magma by volatile, which would spread to large areas with small friction with the surface that would increased with the increase of viscosity caused by the loss of volatile and decreasing of temperature, developing coherent structures as lava flows.

Perfil longitudinal e a aplicação do índice de gradiente (RDE) no rio dos Patos, bacia hidrográfica do rio Ivaí, PR

This paper presents the results of the longitudinal profile analysis and the application of gradient index (RDE) in the Patos River, a tributary of the Ivaí River basin, PR. The goal is identify and quantify the anomalous zones along river course concerning their genesis - activity neotectonic or/and lithological imposition. The Patos River has a length of 127 km and a relief amplitude of 660 m, The occurrence of an important knickpoint in the middle course the Patos River can be divided into two stretches. Of the 22 sections measured, 10 were considered anomalous, distributed in both upper and lower course. In the upper course, over a basaltic bedrock of the Serra Geral Formation the RDE values are lower than those in the lower course, where river flows over sedimentary rocks of the Terezina Formation. The 2 nd order anomalies are related to lithological changes, relief alignments and channel confluences - as in the case of São João River. The 1st order anomalies are linked to differences in rock resistance associated with structural control, which provides the formation of waterfalls.

Revisando os efeitos da concentração de oxigênio sobre o desenvolvimento embrionário

Despite the fact that the processes of embryo development and implantation of mammals do not occur in atmospheric tension in vivo, it is common practice in laboratories for in vitro fertilization (IVF) the culture of embryos in an oxygen tension of 20%. The discrepancy between the tensions of oxygen leads to important discussions about their effects in vitro embryo development. It is believed that the culture of embryo in atmospheric oxygen tension can be detrimental to the quality of the data for predisposing them to the negative interference of reactive oxygen species (ROS), resulting in oxidative stress, leading to deleterious effects on metabolism embryo gene expression and blastocysts grown in those conditions. Faced with arguments for and against the culture of embryos in vitro oxygen tensions similar to those found in vivo, this revies article aims to condense and discuss the literature concerning the influence of oxygen tension on the quality of in vitro culture.