127 resultados para STM TIPS
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Epithelial cells from involuting rat ventral prostate (VP) express Matrilysin (MMP-7) mRNA. Herein, we investigated by immunohistochemistry the NIMP-7 protein location and its association with tissue changes following castration in the VP. Normal and castrated adult male Wistar rats were sacrificed at different times after surgery. VP was examined by immunocytochemistry and immunoprecipitation. Castration promoted a shrinking of prostate ducts with an extensive stromal remodeling. In the VP from normal rats, MMP-7 immunoreactivity was found in epithelial secretory granules. Three days after castration, immunostaining for MMP-7 was found in both the epithelial secretory granules and in the stroma just below the epithelium, mainly at the distal ductal tips. At seven and 21 days after castration, the immunostaining for MMP-7 was found only in the stromal space. Immunoprecipitation confirmed the specificity of the primary antibody by rescuing a pro-enzyme form (28 kDa) in the prostate extracts. The present results suggest that MMP-7 participates in the epithelial-stromal interface remodeling of the ventral prostate during the involution achieved by castration, probably in the degradation of components of the epithelial basement membrane. (c) 2007 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.
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Rhizoctonia solani AG-1 IA causes leaf blight on soybean and rice. Despite the fact that R. solani AG-1 IA is a major pathogen affecting soybean and rice in Brazil and elsewhere in the world, little information is available on its genetic diversity and evolution. This study was an attempt to reveal the origin, and the patterns of movement and amplification of epidemiologically significant genotypes of R. solani AG-1 IA from soybean and rice in Brazil. For inferring intraspecific evolution of R. solani AG-1 IA sampled from soybean and rice, networks of ITS-5.8S rDNA sequencing haplotypes were built using the statistical parsimony algorithm from Clement et al. (2000) Molecular Ecology 9: 1657-1660. Higher haplotype diversity (Nei M 1987, Molecular Evolutionary Genetics Columbia University Press, New york: 512p.) was observed for the Brazilian soybean sample of R. solani AG-1 IA (0.827) in comparison with the rest of the world sample (0.431). Within the south-central American clade (3-2), four haplotypes of R. solani AG-1 IA from Mato Grosso, one from Tocantins, one from Maranhao, and one from Cuba occupied the tips of the network, indicating recent origin. The putative ancestral haplotypes had probably originated either from Mato Grosso or Maranhao States. While 16 distinct haplotypes were found in a sample of 32 soybean isolates of the pathogen, the entire rice sample (n=20) was represented by a single haplotype (haplotype 5), with a worldwide distribution. The results from nested-cladistic analysis indicated restricted gene flow with isolation by distance (or restricted dispersal by distance in nonsexual species) for the south-central American clade (3-2), mainly composed by soybean haplotypes.
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The trifluralin is an agent that promotes a cellular damage due to its direct action on the microtubules. This action leads to a decontrol in the cellular division, bringing about polyploid cells. In this work, we show the evidences that the exceeding genetical material of theses polyploidizated cells tends to be eliminated from the nucleus in the form of micronucleus. Our analyses prove this fact, both by the presence of a number of cells carrying micronucleus, and by the evidences of the elimination of the exceeding material itself, after exposition of the Allium cepa root tips tested with several concentration of trifluralin herbicide. It was noticed that the residual concentration induced a number of polyploid cells, micronuclei and mini cells. Inferences about the implications of the elimination of genetic material from micronuclei, such as cell viability and apoptosis, are also presented. (c) 2007 Elsevier B.V. All rights reserved.
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The effects of chronic alcohol ingestion on the secretory epithelium of the seminal vesicle were studied in rats (Rattus norvegicus). Male adult albino Wistar rats were divided into two groups: alcoholic and control. Tips of the seminal vesicle were removed and prepared for light and electron microscopy. Ultrastructural observations on the epithelial cells of the seminal vesicle showed reduced epithelial cell size, decreased apical secretory vacuoles, irregularly shaped nuclei with deep infoldings, increased lipid droplets and dense bodies, a small number of microvilli covering the cell surface, and signs of degeneration. In addition to the hormonal effects, alcohol may act on the secretory epithelium of the seminal vesicle.
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Aim To assess the histological response associated with grey mineral trioxide aggregate (GMTA) and zinc oxide eugenol (ZOE) as root-end filling materials in teeth where the root canals were not filled and the coronal access cavities were not restored.Methodology Periapical lesions were developed in 24 premolar teeth in three dogs. The root canals were prepared and half of them were dried, filled and the coronal access restored (closed). The remaining teeth were not root filled and no coronal restoration was placed (open). Apical root-end resections were performed 3 mm from the apex, and root-end cavities were prepared with ultrasonic tips. These were randomly filled with either ZOE or GMTA in the same number of specimens using MAPSYSTEM device. After 180 days the animals were killed and blocks of tissues removed and processed for histological examination. Periradicular tissue reaction was evaluated, including severity of inflammation and cementum formation. Statistical analysis was performed using ANOVA analysis and Tukey's test.Results A significant difference was found between the levels of inflammation in the periradicular tissues of the GMTA/closed group, compared with the ZOE/open and ZOE/closed groups (P < 0.05) but not between GMTA/closed and GMTA/open groups. Cementum formation was not found over any ZOE specimens but over MTA in all specimens. No microorganisms were found in the interface between the material and the dentinal walls.Conclusions GMTA was associated with less periapical inflammation and tissue response when used as a root-end filling material, even when no root filling or coronal restoration was present.
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Purpose : the aim of this study was to evaluate the effect of nozzle angle and tip diameter on the cutting efficiency of an air abrasion system. Materials and Methods: Thirty-six extracted human third molars were air-abraded with the PrepStar microabrasion machine using a handpiece with either 80degrees or 45degrees nozzle angles with 0.38 or 0.48 nun tip orifice diameters. The following parameters were held constant: abrasive particle size (27 mum), air pressure (80 psi), distance (2 mm.) and duration (15 seconds). The cutting efficiency was compared using enamel, dentin and cementum substrates. Width and depth of the cutting patterns were analyzed and measured using scanning electron micrographs. Results: Statistical analysis using three-way ANOVA and Duncan's Multiple Range test revealed that the width of the cuts was significantly greater when the cavities were prepared using the 45degrees nozzle angle. Significantly deeper cavities were produced with the 80degrees nozzle angle. The tip orifice of the nozzle influenced the cutting efficiency in softer substrates, dentin and cementum. Precise removal of hard tissue is best accomplished using the 80degrees angle nozzle tips for all types of tooth surfaces, enamel, dentin and cementum.
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Zinc (Zn) uptake kinetics and root and leaf anatomy were studied in coffee trees grown in nutrient solutions with or without Zn. Leaves and roots were sampled and cuts were made in the medium part of the leaves and in root tips and observed under an optical microscope. Plants grown without Zn showed an increase in root and in root stele diameter. There was also an increase in epidermis thickness and in the cross-sectional area of the cortex and stele due to Zn deficiency, but the diameter of xylem vessels was decreased. An increase in root cortex and stele diameter provided for an increased surface for nutrient uptake. Accordingly, C(min) was decreased from 13.8 to 3.4 mu mol L(-1) and V(max) increased from 0.50 to 2.1 mu mol cm(-2) h(-1) .
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This work reports the preparation and characterization of (SnO2) thin films doped with 7 mol% Sb2O3. The films were prepared by the polymeric precursor method, and deposited by spin-coating, all of them were deposited on amorphous silica substrate. Then, we have studied the thickness effect on the microstrutural, optical and electric properties of these samples. The microstructural characterization was carried out by X-ray diffraction (XRD) and scanning tunneling microscopy (STM). The electrical resistivity measurements were obtained by the van der Pauw four-probe method. UV-visible spectroscopy and ellipsometry were carried out for the optical characterization. The films present nanometric grains in the order of 13 nm, and low roughness. The electrical resistivity decreased with the increase of the film thickness and the smallest measured value was 6.5 x 10(-3) Omega cm for the 988 nm thick film. The samples displayed a high transmittance value of 80% in the visible region. The obtained results show that the polymeric precursor method is effective for the TCOs manufacturing.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Indium-tin oxide nanowires were deposited by excimer laser ablation onto catalyst-free oxidized silicon substrates at a low temperature of 500 degrees C in a nitrogen atmosphere. The nanowires have branches with spheres at the tips, indicating a vapor-liquid-solid (VLS) growth. The deposition time and pressure have a strong influence on the areal density and length of the nanowires. At the earlier stages of growth, lower pressures promote a larger number of nucleation centers. With the increase in deposition time, both the number and length of the wires increase up to an areal density of about 70 wires/mu m(2). After this point all the material arriving at the substrate is used for lengthening the existing wires and their branches. The nanowires present the single-crystalline cubic bixbyite structure of indium oxide, oriented in the [100] direction. These structures have potential applications in electrical and optical nanoscale devices.
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In the laboratory of cytogenetics of the DBAA-UNESP we are studying the karyotipe of some Brazilian Palms. To determine the best protocol, methods of seed germination, inhibition of mitosis, time to pick up the roots and staining were analyzed. The results shown that the seed germination in sphagnum is effective to achieve good roots. The best time to collect the root tips is between 11 to 12 AM., when there are more cell metaphases. The inhibition of mitosis cycle at metaphases may be effective both with 8-hydroxiquinoleine (0,03% -5 hours) or with cold water (0°C - 18-20 hours). The staining with Giemsa 2% showed the best chromosome figures in the metaphases. Now, to get good metaphases slides the method in use in the lab is: 1) seed germination in sphagnum at room temperature and high humidity; 2) The major roots are cut maintaining at least 5 cm, because this technic allows new emergence of roots, increasing the number of roots collected per germinated seed, that is very important in some species with poor germination rates; 3) To get the mitosis inhibition we are using cold water (0°C) treatment for 18-20 hours, following the standard protocols for conservation and hydrolysis; or enzyme digestion with pectinasecellulase 4) the staining procedures are made using Giemsa 2%. The Brazilian palms species studied and their respective chromosome number were: Aiphanes acanthophylla (2n=30), A. caryotaefolia (2n=30), Syagrus quinquifaria (2n=32), S. coronata (2n=32), S. romanzoffiana (2n=32), Euterpe edulis (2n=36), E. oleracea (2n=36), Copernicia prunifera (2n=36), Scheelea lauromuelleriana (2n=32) and Bactris gasipaes (2n=30).
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This study assessed cavity preparations produced with different air abrasion tip parameters. Twelve test groups of extracted teeth were prepared to evaluate the parameters of 80 degrees or 45 degrees nozzle angles and 0.38 or 0.48 mm inner tip diameters. All other factors were held constant. A device was made to hold the specimen and air abrasion handpiece that standardized the distance and position relative to the tooth and time of application. The cavities were evaluated by assessing the rounding of the cavosurface margins and cavity floor. Measurements of cavosurface angles and the angle of concavity were made at the deepest portion of the abraded surface using scanning electron micrographs. The cavosurface angles were compared using paired t-test, and the effects of the tip design parameters were analyzed by ANOVA and Duncan's Multiple Range test. From the cavity patterns found in this study, the authors suggest that 80 degrees angle tips are more appropriate than 45 degrees angle tips for making narrow, deep cuts for preventive resin restorations. Conversely, when shallow preparations are needed, as in the case of Class V cavity preparations, cutting patterns of 45 degrees angle tips are more suitable.
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Two wild diploid (2n = 20 chromosomes) and self-pollinating Arachis species, Arachis Pintoi Krapov and W.C. Gregory and A. villosulicarpa Hoehne were submmited to C-band technique to karyotype analyses. Root tips were employed in the analyses. Morphometric data chose that chromosome lengths varied from 3.12 in A. villosulicarpa to 1.45 in A. Pintoi. Karyotype formula obtained was 10sm to A. Pintoi and 9sm + 1m to A. villosulicarpa. There was a predominance of pericentromeric C-band in all mitotic metaphasic chromosomes in both species. Besides C-band values, both species still did not differ in respect to chromosome absolute and relative lengths, centromeric index, symmetry index and total karyotype haploid length. C-band and morphometric data did not show strong or significant differences which could separate these two species of peanut which belong to evolutive different sections.
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This study evaluated the characteristics of spray produced by Yamaho nozzle tip'D'series. The droplet size of nozzle tips D3, D4, D5, D6 and D8 were evaluated at 703, 1.050, 1.406, 1.758, 2.110, 2.461 e 2.813 kPa pressures (100, 200, 250; 350, e 400 psi) by means of laser equipment, as well as the flow rate of nozzle tip at the pressures of 702, 1.125, 1.406, 1.828, 2.110, 2.532 e 2.813 kPa (100, 160, 200, 260,300; 360 e 400 psi) which were compared with values indicated by manufacturer. The droplet produced at all pressures presented a very fine spray, which in agriculture may promote losses by evaporation and drift. For all nozzle tips, except D8 in pressures 1.828, 2.532 e 2.813 kPa, the difference between the observed flow rate indicated by the manufacturer was higher than 5%. The paper demonstrates that the nozzle tip tested, in spite of not having uniform flow rate, may promote the contamination of spray operator and environment due to the droplet spectrum produced.
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The aim of this paper was verifying the effect of the Equex STM Paste and EDTA addition to a Tris-egg yolk extender, on the postthaw goat sperm viability. Nine semen samples of two adult goats were collected by artificial vagina and cryopreserved. It was also objective of this study, to evaluate the utilization of a soybean lecithin based commercial extender (Bioexcell® - IMV, L'Aigle, French) for the goat semen freezing. They were formed five experimental groups: TRIS; TRIS+EDTA; TRIS+EQUEX; TRIS+EDTA+EQUEX e Bioexcell. After evaluation, the semen was diluted in the five extenders and packed in 0.25mL straws with 100 million of motile spermatozoa. The samples were cooled at 0,46°C/min to 5°C, submitted at 75min of equilibration time and frozen in liquid nitrogen vapour. The thawing was accomplished in 37°C water bath for 50s. There were no differences (P>0,05) on the means of post-thaw total and progressive sperm motility among the groups TRIS, TRIS+EQUEX and TRIS+EQUEX+EDTA. The Bioexcell group obtained the least (P<0,05) percentage of post-thawing total and progressive sperm motility. After the thermotolerance test, it was observed the greatest (P<0,05) rates of total and progressive sperm motility in the Equex STM groups (TRIS+EQUEX and TRIS+EQUEX+EDTA). Thus, it can be affirmed that the Equex addition promotes better maintenance rates in the pos-thaw sperm viability, when compared with the extenders that did not contain it.