201 resultados para Axial Length
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The milk is an important food because it contents Conjugated Linoleic Acids (CIA). These fatty acids are synthesized in mammary gland under action of the enzyme Stearoyl CoA-Desaturase (SCD) and have showed some positive effects in human disease prevention and treatments. A variation of CLA in milk fat exists and can be partially explained by the different levels of expression of SCD. The aim was to study part of the encoding regions of SCD's gene using PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism). Genomic DNA was extracted from lactating Murrah females. After this, PCR reactions were made by using primers Z (sic) (sic) D1 that encloses exon I, II and intron I. The fragments amplified are composed by 938 pb. Then, RFLP techniques were applied in the fragments using the restriction enzymes Pst I and Sma I. The enzyme Pst I has generated fragments of 788pb and 150bp and the Sma I has generated fragments of 693pb and 245pb. All the animals showed the same migration standard for both enzymes, characterizing a genetic monomorphism for this region of SCD gene. The analysis determined that there aren't genetic differences between these animals in the studied regions by using Pst I and Sma I enzymes.
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Guazuma ulmifolia is as popular reforestation tree all over Latin America. It is characteristic of the initial stages of the secondary sucession and presents potential utility in the restoring of degraded areas. There is no information about fruit,seed and seedling morphology, which is of fundamental importance for identification, extraction, management and seed germination as well as for the characterization of post-seminal development and normal seedling pattern. To obtain such information, external fruit, and external and internal seed structures were studied considering shape, size, micropile and embryo localization; and tegumentar structures. All stages of this work were conduced in the Universidade Estadual Paulista (UNESP), Campus of Jaboticabal city. The fruits were collected in a mixed plantation in Jaboticabal city, State of São Paulo, Brazil. For the bio metric study eight repetitions of ten fruits and eight repetitions of 100 seeds were utilized. For seed internal traits study, 50 seeds were drenched in a distiled water, cut, and observed with a scanning electron microscope and a stereomicroscope, For post-seminal study ten repetitions of seven seeds were scarificated chemically with sulphuric acid during 50 min, and placed to germinate ina culture medium, at 30 degrees C, and eight hours of photoperiod. We found elipsoid, woody, indehiscent, pentacarpelar fruits, with a mean lenght of 22.61 mm (diameter 24.88 mm) and 64.0 seeds per fruit. Seed shape varies, mean length is 3.07 mm (width of 2.36 mm). The seed is bitegumented, tegmic, with a continuous, axial and curved embryo. The germination is epigeal and the seedlings are fanerocotiledoneus. Drawings of all stages are included.
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For the molecular diagnosis of Plasmodium vivax variants (VK210, VK247, and P. vivax-like) using DNA amplification procedures in the laboratory, the choice of rapid and inexpensive identification products of the 3 different genotypes is an important prerequisite. We report here the standardization of a new polymerase chain reaction/restriction fragment length polymorphism technique to identify the 3 described P. vivax circumsporozoite protein (CSP) variants using amplification of the central immunodominant region of the CSP gene of this protozoan. The simplicity, specificity, and sensitivity of the system described here is important to determine the prevalence and the distribution of infection with these P. vivax genotypes in endemic and nonendemic malaria areas, enabling a better understanding of their phylogeny. (c) 2007 Published by Elsevier B.V.
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The gerbil (Meriones unguiculatus) is a rodent native of the and regions of Mongolia and China. Because the gerbil can be easily bred in laboratory conditions, this species has been largely used as an experimental model in biomedical research. However, there is still little information concerning the testis structure and function in the gerbil. In this regard, we performed a detailed morphofunctional analysis of the gerbil testis and estimated the spermatogenic cycle length utilizing H-3-thymidine as a marker for germ cell progression during their evolution through the spermatogenic process. The stage frequencies of the XII stages characterized according to the acrosome formation and development were (I-XII) 13.8, 10.1, 8.1, 7.8, 4.0, 11.2, 7.5, 7.1, 5.9, 7.6, 8.1, and 8.9. The mean duration of each seminiferous epithelium cycle was determined to be 10.6 +/- 1.0 days and the total duration of spermatogenesis, based on 4.5 cycles, was approximately 47.5 days. The volume density of tubular and interstitial compartments was approximately 92% and 8%, respectively. Based on the volume occupied by seminiferous tubules in the testis and the tubular diameter, about 9 and 18 m of seminiferous tubules were found per testis and per gram of testis, respectively. Twelve primary spermatocytes were formed from each type A1 spermatogonia. The meiotic index was 2.8, indicating that 30% of cell loss occurs during meiosis. The number of Leydig and Sertoli cells per gram of the testis was 28 million and each Sertoli cell was able to support approximately 13 spermatids. The daily sperm production per gram of testis (spermatogenic efficiency) was 33 million. Taken together, these data indicate that, mainly due to the high seminiferous tubule volume density and Sertoli cell support capacity for germ cells, the gerbil presents high spermatogenic efficiency compared with other mammalian species already investigated. The data obtained in the present study might provide the basis for future research involving the reproductive biology in this species.
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Acicular monodispersed Fe1-xREx (RE= Nd, Sm,Eu,Tb;x=0, 0.05, 0.10) metallic nanoparticles (60 +/- 5 nm in length and axial ratio similar to6) obtained by reduction of alumina-coated goethite nanoparticles-containing rare earth (RE) under hydrogen flow are reported. Alumina and maghemite thin layers on particle surface were used to protect the goethite particles against sintering and oxidation, respectively. Al and RE additions were obtained by successive heterocoagulation reactions. Aluminum sulfate (10 at.% based on Fe) was dissolved in water and the pH adjusted to 12.5 with NaOH solution. Goethite particles were suspended in this solution and CO2 gas was blown into the slurry to neutralize it to a pH 8.5 or less. Particles were purified and dehydrated to effect transformation to alumina-coated hematite nanoparticles, which were re-suspended in aqueous solution in which RE sulfate (0-0.15 at.% based on Fe) has been dissolved, and the pH increased by ammonia aqueous solution addition. Resulted alumina-coated RE-doped hematite nanoparticles were reduced to metal at 450 degreesC/12 h under hydrogen flow and passivated with nitrogen-containing ethanol vapor at room temperature. Acicular monodispersed metallic nanoparticle systems were obtained and the presence of Al and RE were confirmed by induced-coupled plasma spectrometry analysis. X-ray diffraction, Mossbauer spectroscopy, and magnetization data are in agreement with the nanosized alpha-Fe core in a bcc structure, having a spinel structure, gammaFe(2)O(3), with thickness similar to1.5 run on particle surface. Main magnetic parameters showed saturation magnetization decreases and significant increasing in the coercive field with the RE composition increases. Magnetic properties of these particles, similar to40% smaller than those commercially available, suggest a decrease in the bit-size for high-density magnetic or magneto-optics recording media application. (C) 2004 Published by Elsevier B.V.
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The design of the present study enabled the authors to distinguish between the possible effects of movement displacement and trajectory length on the pattern of final positions of planar reaching movements. With their eyes closed, 9 subjects performed series of fast and accurate movements from different initial positions to the same target. For some series, the movements were unconstrained and were therefore performed along an approximately straight vertical line. For other series, an obstacle was positioned so that trajectory length was increased because of an increase in movement curvature. Ellipses of variability obtained by means of principal component analysis applied to the scatter of movement final positions enabled the authors to assess the pattern of movement variable errors. The results showed that the orientation of the ellipses was not affected by movement displacement or by trajectory length, whereas variable errors increased with move ment displacement. An increase in trajectory length as a consequence of increased curvature caused no change in variable error. From the perspective of current motor control theory, that finding was quite unexpected. Further studies are required so that one can distinguish among the possible effects of various kinematics, kinetics, and other variables that could affect the pattern of variable errors of reaching movements.
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A new synthetic route for producing monodispersed and single crystal acicular goethite particles with small particle size and a high axial ratio adequate for use as a high density magnetic recording media precursor is reported. It essentially consists of the hydrolysis of alkaline Fe-III suspensions in the presence of carbonate by a three-step procedure, the formation of ferrihydrite primary particles, the ferrihydrite dissolution and nucleation of goethite, and the growth of the goethite nuclei. Changing the temperature of heating during ageing achieved a separation of the two last stages. X-Ray diffraction, transmission electron microscopy, infrared spectroscopy and surface area data have been used to determine the mechanism responsible for the formation of goethite particles with controlled size and shape. The best conditions to prepare monodispersed goethite particles have been established. The results show that uniform goethite particles of (a) 60 nm length with an axial ratio of 6 and (b) 230 nm length with a high axial ratio of 10, can be obtained by using an [OH]/[Fe] molar ratio of 0.35 in the initial suspensions with carbonate or sodium hydroxide, respectively. The [OH]/[Fe] molar ratio determines the particle size and elongation by controlling the hydrolysis reaction rate, while the carbonate ions promote a constant [OH] in the solution, keeping the pH around 10 during the entire synthesis process. This procedure, associated with the appropriate temperature control, leads, under certain conditions, to highly homogeneous goethite particles with sizes smaller than those obtained using sodium hydroxide with the same [OH]/[Fe] ratio.
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The feasibility of Portland cement analysis by introduction of slurries in an inductively coupled plasma optical emission spectrometer (ICP-OES) with axial viewing has been evaluated. After a fast manual grinding of the cement samples, owing to the pulverized state of this material, 0.1% m/v slurries were prepared in 1% v/v HCl. The calibration was performed adopting two strategies: one based on slurries prepared from different masses (50, 75, 100 and 125 mg) of a Portland cement standard reference material (NIST SRM 1881), and the other one based on aqueous reference solutions. A complete analysis of cement for major (Al, Ca, Fe, Mg and Si), minor and trace elements (Mn, P, S, Sr and Ti) was accomplished. Both strategies led to accurate results for commercial Portland cement samples, except for Si and Ti. for which the calibration with aqueous reference solutions resulted in low values. Applying a paired t-test it was shown that most results were in agreement at a 95% confidence level with a conventional fusion decomposition procedure. The ICP-OES with axial viewing and end-on gas configuration for removal of the recombination plasma zone was effective for cement slurry analysis without any undesirable particle deposition in the pre-optics interface and without severe spectral interferences. (C) 2002 Elsevier B.V. B.V. All rights reserved.
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This work presents a comparative analysis about the behaviour of pile caps supported by 3 piles subjected to axial loading. Piles with 20 cm and 30 cm diameters were analysed. The main reinforcement was maintained in all the specimens, however, the arrangement of the secondary reinforcement varied. The main reinforcement consisted of steel bars connecting the piles. The secondary reinforcement was made up of: (a) bars going through the piles and through the projection of the column, (b) bars forming a network, and (c) vertical and horizontal stirrups. The main objective was the observation of the pile cap behaviour regarding the cracks and the modes of rupture. The real scale specimens were subjected to experimental tests until failure by rupture. Instruments were placed with the aim to obtain the displacement of the bases, the strains in the main and secondary reinforcement bars, in the compression struts, in the lower and upper nodal zones and in the sides of the caps. None of the caps reached failure by rupture with a load less than 1.12 times the theoretical load. The specimens ruptured due to the cracking of the compression strut and/or the yielding of the reinforcement bars in one direction.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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We consider an extension of the axial model where local gauge symmetries are taken into account. The result is a mixing of the axial and Schwinger models. The anomaly of the axial current is calculated by means of the Fujikawa path integral technique and the model is also solved. Besides the well-known features of the particular models (axial and Schwinger) an effective interaction of scalar and gauge fields via a topological current is obtained. This term is responsible for the appearance of massive poles in the propagators that are different from those of both models.
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The premature loss of primary teeth may harm the normal occlusal development, although there are debates relating to the necessity of using space maintainer appliances. The aim of the study is to evaluate the changes in the dental arch perimeter and the space reduction after the premature loss of the lower first primary molar in the mixed dentition stage. The sample consists of 4 lower arch plaster models of 31 patients, within the period of pre-extraction, 6, 12 and 18 months after the lower first primary molar extraction. A reduction of space was noted with the cuspid dislocation and the permanent incisors moving toward the space of the extraction site. It was concluded that the lower first molar primary premature loss, during the mixed dentition, implicates an immediate placement of a space maintainer.