279 resultados para E(L) parameters


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Starting from the well established form of the Dirac action coupled to the electromagnetic and torsion field we find that there is some additional softly broken local symmetry associated with torsion. This symmetry fixes the form of divergences of the effective action after the spinor fields are integrated out. Then the requirement of renormalizability fixes the torsion field to be equivalent to some massive pseudovector and its action is fixed with accuracy to the values of coupling constant of torsion-spinor interaction, mass of the torsion and higher derivative terms. Implementing this action into the abelian sector of the Standard Model we establish the upper bounds on the torsion mass and coupling. In our study we used results of present experimental limits on four-fermion contact interaction (LEP, HERA, SLAC, SLD, CCFR) and TEVATRON limits on the cross section of new gauge boson, which could be produced as a resonance at high energy pp̄ collisions. © 1998 Elsevier Science B.V. All rights reserved.

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Fourteen complexes in the series [RuCl2(CO)(L)(PPh3)2] (where L = N-heterocycles) have been prepared and characterized by IR and NMR spectroscopies, and cyclic voltammetry. A good correlation is found between observed and calculated electrochemical potentials; E1/2 vs pKa or (Gp, σm for a series of similar ligands. It is now reported that the carbonyl stretching frequency, νCO, and the 13C and 31P NMR signals do not correlate well with any of the physico-chemical parameters used (E1/2, Taft's and Hammett's parameters). This behaviour is probably due to the characteristics of the Ru(II) species, which does not transmit the steric and electron donor/acceptor properties of the ligands to the carbonyl group, or because the measurements are not able to detect the effect induced by the changes in the ligand L. Indeed, good correlations are obtained when the measurements directly involve the metal centre, as is the case in the E1/2 measurements. Crystals of o[RuCl2(CO)(4-pic)(PPh3)2] are monoclinic, space group P21/n, a = 12.019(2), b = 13.825(3) and c = 22.253(3) . The structure was solved by the Patterson method and was refined by full-matrix least-squares procedure to R = 0.054 and Rw = 0.055, for 2114 reflections with I > 3σ(I). For L = 2-acetylpyridine and 2-methylimidazole, complexes with formulae [RuCl2(CO)(L)(PPh3)] · L and [RuCl2(CO)(L)2 (PPh3)], respectively, were obtained. © 1998 Elsevier Science Ltd. All rights reserved.

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We have studied the bevahior of the phenomenological 4f-4f intensity parameters in compounds of the Nd ion with glycine, L-aspartic acid, L-glutamic acid, L-histidine, DL-malic acid and Aspartame™ in aqueous solution, as a function of the pK values and partial charges on the oxygens of the carboxylate groups of these molecules. The results are discussed and qualitatively interpreted in terms of the forced electric dipole and dynamic coupling mechanisms of the 4f-4f intensities, thus indicating that the forced electric dipole mechanism is dominant.

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The present work aimed to verify the early rooting development and the root production in rosemary's (Rosmarinus officinalis L.) cuttings under the influence of treatments with sythetics auxins, boric acid and collecting time. The branches were collected at the end of the season and the stakes were prepared and placed into solutions containing NAA or IBA (25, 50, 75 and 100 pppm) without and with boric acid and then removed to a chamber of nebulization (all experimental work). In all the experimentes, the branches were collected after 30 days, the mean number of rooted cuttings was calculated, along with the mean number of roots per stakes and the dry weight of roots. The end of winter outstood as the best season for all analysed parameters.

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Chemical characterization as well as spectroscopical study of the L-histidine-europium(III) complex were developed both experimental and theoretically. Molecular mechanics (MM) simulation was performed in order to have indication of the compound structure and the Eu 3+ chemical environment. The Simple Overlap Model (SOM) was applied to predict spectroscopic quantities as 5D 0→ 7F 0/ 5D 0→ 7F 2 intensity ratio, 5D 0→ 7F 1 transition splitting and the intensity Ω λ parameters (λ = 2 and 4). Satisfactory results are obtained with 0.1 and 2/3 as the effective charges of the nitrogen (gN) and oxygen (gO) respectively, and their polarizabilities (α) depend on the distance. © 1999 Elsevier Science B.V. All rights reserved.

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Seed ageing is natural phenomenon that occurs in all seeds, including those stored in dry and low temperature rooms. Phaseolus vulgaris L. cv. 'Carioca' seeds harvested in five different years were stored in at 15°C. Seed samples were germinated and evaluated according to The Brazilian Rules for Testing Seeds. The newest seed sample was submitted to artificial ageing. Small (∼1g) samples of all materials (naturally and artificially aged) were ground and proteins extracted. Equal quantities of protein were loaded onto the gels and electrophoresis carried out. Although seeds submitted to 24, 48, 72 and 96 hours of artificial ageing did not show any statistical difference (5%) in relation to unaged seeds in physiological parameters related to emergence, some statistically different parameters related to dry matter and length of shoots and roots occurred. A 24 h of artificial ageing at 41°C improved these factors. Protein patterns were changed after 72 h of artificial ageing and naturally aged seeds showed alterations after two years storage at 15°C. Aged seeds, naturally and artificially, had decreasing germination, vigour, and changes in the characteristic banding pattern of proteins. Physiological parameters and electrophoresis examination showed that for naturally aged seeds physiological parameters were more sensitive while artificially aged seeds, (41°C/100% RH), had electrophoretic profiles that were more efficient for seed lot discrimination.

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Objective: to assess the efficacy and safety of the use of nebulized L-epinephrine associated with dexamethasone in post-intubation laryngitis. Method: we carried out a prospective, randomized, double-blind, placebo controlled study with two cohorts of patients with postintubation laryngitis graded 3 to 6 by Downes and Raphaely score and during two years. Our population was divided into two groups: A and B; both groups received intravenous dexamethasone and nebulized saline with (group B) and without (group A) L-epinephrine. The efficacy was assessed by Downes and Raphaely's score. The side effects of epinephrine were evaluated according to occurrence of arrhythmia, to increased blood pressure, and to average heart rate of group B in comparison to group A. Results: twenty-two patients were included in group A (average score = 4.8) and 19 in group B (average score = 5.2). During treatment, 3 patients in group A presented a score of 8 and were reintubated. This group also showed higher clinical scores than group B during the first two hours of the protocol; these results were not statistically significant. No side effects were observed due to epinephrine. The gasometric parameters were adequate in both groups, but better in the control group. Conclusions: we did not observe increased efficacy for the treatment of post-intubation laryngitis when nebulized L-epinephrine was used simultaneously with intravenous dexamethasone. Some indicators, however, did present a favorable trend when combined therapy was used and should be submitted to further evaluation.

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In this study we consider the SIS epidemiological model (susceptible-infected-susceptible) in which the transmission and recuperation rates are considered fuzzy sets. The concepts of possibility measures and fuzzy expectancy value are used to obtain the basic reproduction value for infected groups with different viral charge.

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In order to evaluate growth characteristics, adaptability, biomass production, nutrient recycling, nutrient distribution and the ability to regenerate degraded land, a trial using four multipurpose tree species (Leucaena leucocephala, Leucaena diversifolia, Acacia melanoxylon and Mimosa scabrella) was undertaken over two years in a distrophic red yellow latosol (oxisol) following a randomized block experimental design with four replications. At the age of two years, A. melanoxylon and L. diversifolia were the tallest species (5.25 and 4.97 m, respectively) and A. melanoxylon and M. scabrella had the largest diameters at 20 cm from tree base. Mimosa scabrella and A. melanoxylon had the highest dry matter production and quantity of nutrients in the above ground biomass. In all species, the highest nutrient contents were found in the leaves, followed by branches and stems. From all species, the highest Nutrient Utilization Efficiency Indexes were obtained for sulphur, phosphorous, and magnesium; L. diversifolia was the most efficient for nitrogen, potassium, calcium, sulphur, and manganese, while A. melanoxylon was the most efficient for phosphorus, magnesium, boron, iron, and zinc. Litter production levels over a three month period were as follows: M. scabrella > A. melanoxylon > L. diversifolia > L. leucocephala. Litter nutrient content was higher in M. scabrella than in the other species.

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Salting have been a very utilized fish conservation method, however only in the last years the basic mechanism involved in salting fish has been understood. The objectives of this study were determine the addition in brine salt of rosemary leaves, rosemary extracts and tocopherol, and your action in the followed parameters: water activity (Aw), moisture, ash, salt content and TBARS. The results showed that the addition of antioxidants was difficulted the salt absorption, however didn't have differences between rosemary or tocopherol use. In the salting time of 3 hours the values of Aw and salt levels, was respectively: 0.77±0.01 and 14.42±1.69. for control treatment; 0.85±0.02 and 9.09±1.39for rosemary filtrate; 0.78±0.03 and 10.63±0.69 rosemary without filtrating and 0.85±0.02 and 11.96±1.78 tocopherol, showed that didn't grow indigenous bacterias. Lipid oxidation was evaluated by TBARS and the results showed the oxidative effect of salt and the pro oxidant effects of alls antioxidants used in brine salting.

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It was evaluated the energetic efficiency and operational parameters of a windrowing and prismatic baling, both from CASE NEW HOLLAND® operations in sugarcane vegetal residues (green leaves, dry leaves and tops) picked mechanically in green cane. The area belongs to COSTA PINTO MILL (COSAN® Group) which was harvested mechanically by combines in the State of Sao Paulo, Brazil. The geographic location of the area is: Latitude 22°40'30S, Longitude 47°36'38W and Altitude of 605m. The variety was RB 82-5336, planted in 1.40m row spacing, with 78t.ha-1 yield. The vegetal residues analysis obtained 69.93% of leaves, 21.44% of stalks fractions, 2.27% of tops and 6.36% of total strange matter. The vegetal residues values were: gross heat of 18.43MJ.kg-1, low heat of 17.00MJ.kg'1 and useful heat of 12.94MJ.kg-1. The vegetal residues average energetic potential was 342.48GJ.ha-1. The treatments were simple, double and triple windrowing. The use of the rake and prismatic baler to pick up the residues was viable. The simple windrowing treatment presented the best results: effective capacity of 83.06t.ha-1, fuel consumption of 0.18L.t -1 and 99.95% of positive energetic efficiency. The bales obtained in the treatment of triple windrowing presented the largest specific mass average of 221.11kg.m-3. The soil amount in the bales increased with successive windrowing. The baling operation in the triple windrowing treatment obtained better results, presenting the effective capacities of 20.29t.h -1 and 1.45ha.h-1 and fuel consumption of for baled in 1.37L.t-1. The high total energetic efficiency of 99.53% indicates that is technically viable the withdrawal of the vegetal residues.

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The objective of this study was to analyze the sugar cane vegetal residues collection, as well as determining its energetic potential, using a rake and cylindrical baler, both from NEW HOLLAND® under two different windrowing process (simple and double). The field tests were carried out in an area that belongs to COSTA PINTO MILL (COSAN® Group) in the city of Piracicaba, Sao Paulo State, Brazil. The geographic location of the area is: Latitude 22°4030'S, Longitude 47°3633'W and altitude of 605m. From the trash analysis, before the baling, the following average results were obtained: 69.93% of leaves; 2.27% of stalks fractions; 21.44% of tops and 6.36% of total strange matter. The estimated residues yield was 27.01 tons.ha -1 with a gross heat of 18.43 MJ.kg-1, low heat of 17.01 MJ.kg-1, useful heat of 13.32 MJ.kg-1, average moisture of 20.76% and an energetic potential of 494,875.09 MJ.ha-1. In the windrowing operations (simple and double) the averages of the 5 out of 13 analyzed variable presented differences between them in a 1% level of significance in the Tukey Test. The averages comparison of the results for bale's specific mass and the effective capacities (ton.h-1) e (ha.h-1) had been significant at a 5% level in the Tukey Test. The comparisons of the averages for the results had been significant to 1% level. The strange matter averages of the bales did not differed between them.

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Plants that possess a diuretic effect are widely used by people in the treatment of some important diseases as edema and hypertension. The objective of this work was to study the effects of pitanga and jambos aqueous extracts (AE) about the arterial pressure (AP) and urinary flow (V) in normotensive and anesthetized rats. The AE were prepared for the decoction method and administrated for intragastric way in different concentrations: 10%, 15%, 20% and 25%. These concentrations corresponded respectively at doses of 56, 94, 145, 172 mg of pitanga dried extract /Kg and 44, 73, 83, 95 mg of jambos dried extract/Kg. The animals were divided in nine groups with seven individuals (n=7): control (C), P-10%, P-15%, P-20%, P-25%, J-10%, J-15%, J-20% and J-25%. The rats were anesthetized (hypnol 3%) and submitted to tracheotomy. The left carotide artery was catheterized to measure the AP through a mercury manometer, in periods of 15 minutes. The bladder was catheterized for urine collection and to measure the V, in periods of 30 minutes. The experimental protocol was divided in four periods of 30 minutes each: basal (to evaluate of the basal parameters) and experimental (Exp) 1, 2 and 3 (after the administration of the AE). The results were analyzed for ANOVA and Tukey (X±SD, p<0.05). In the C group did have not alteration of the AP basal but the V basal increased. In the experimental groups (AE of P and J) had significative decline in the AP basal: 34% (P-10%), 20% (P-15%), 21% (P-20%), 31% (P-25%), 24% (J-10%), 20% (J-15%) 16% (J-20%) and 29% (J-25%). Moreover, the administration of AE increased the V basal in: 280% (P-15%) and 192% (J-20%). The results showed that the plants evaluated are hypotensive and diuretic.

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The vegetal species, Allium cepa, known as onion, is widely used in the folk medicine as diuretic, besides it has been used on the bronchitis, cough, cardiovascular diseases and hypertension treatment. In this study we evaluate the onion aqueous extract (AE) effect on water flow and electrolytes in anesthetized Wistar rats, besides we also evaluate arterial pressure alterations. Two groups were studied: Group 1 (control) - oral tratment with 1.0 mL of distilled water, and Group 2 (experimental) - oral treatment with 1.0 mL of AE 20%. The rats were anesthetized and we canulate the trachea, left carotide artery (for arterial pressure measurement and blood collecting), jugular vein (to execute inulin perfusion - to register glomerular filtration), and urinary bladder (to collect urine). The Group 1 results had shown that the animals had not presented significant alterations (p>0.05) in the analyzed parameters. The animals of Group 2 had a significant reduction (p<0.05) in the arterial pressure (22.0%). However, there were not significant alterations in renal parameters (p>0.05). These results show that the treatment with the AE lead a hypotensor effect in anesthetized Wistar rats, but not followed by renal parameters alterations.

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Many plants, even without scientific confirmation, are used in Brazil as hypoglycemic. The objective of the present work was to study the influence of the Allium sativum treatment, plant known popularly as garlic, on characteristic biochemical parameters in streptozotocin-induced diabetic rats. Female Wistar rats were injected with 40 mg kg-1 streptozotocin (STZ). Oral administration of an aqueous extract of A. sativum was given to the diabetic animals in 2 doses: 200 and 400 mg kg-1 (n=6 animals/group). Diabetic rats given distilled water constituted the control group. After 28 days of treatment, the female rats were anesthetized and died by decapitation for collection of the blood for biochemical determinations and retreat of liver samples for hepatic glycogen dosage. The treatment with Allium sativum in the doses of 200 and 400 mg kg-1 alter no concentrations of total proteins, hepatic glycogen, triglycerides and VLDL, but it promoted reduction in the total cholesterol rate (control=280.5 ± 30.9; 200 mg kg-1 A. sativum =169.9 ± 19.5 and 400 mg kg-1 A. sativum =148.4 ± 26.6 mg dL-1) and LDL (control=128.8± 25.3; 200 mg kg-1 A. sativum = 41.4 ± 16.2 and 400 mg kg-1 A. sativum=42.0 ± 26.0 mg dL-1). The extract presented beneficial effect because it decreased 13.0% of glycemia in the highest dose. Therefore, the of garlic extract reduced the HDL concentration in two tested doses (control= 81.4 ± 30.2; 200 mg kg-1 A. sativum=49.6 ± 14.3 and 400 mg kg-1 A. sativum=41.7 ± 16.1 mg dL -1), presenting impaired effect. Thus, the garlic extract showed efficiency in the analyzed experimental conditions, and it could be used as complementary therapy to diabetic patients.